GRADE 8 DAILY LESSON LOG Grade Level 8 Learning Area MATHEMATICS Quarter FIRST School Teacher Teaching Dates and Time Session 1 Session 2 Session 3 Session 4 I. OBJECTIVES 1. Content Standards The learner demonstrates understanding of key concepts of factors of polynomials, rational algebraic expressions, linear equations and inequalities in two variables, systems of linear equations and inequalities in two variables and linear functions. The learner is able to formulate real-life problems involving factors of polynomials, rational algebraic expressions, 2. Performance linear equations and inequalities in two variables, systems of linear equations and inequalities in two variables and Standards linear functions, and solve these problems accurately using a variety of strategies Factors completely different Factors completely different Factors completely different Factors completely different 3. Learning types of polynomials types of polynomials types of polynomials types of polynomials Competencies / (polynomials with common (polynomials with common (polynomials with common (polynomials with common Objectives monomial factor , difference monomial factor , difference monomial factor , difference monomial factor , difference of two squares, sum and of two squares, sum and of two squares, sum and of two squares, sum and difference of two cubes, difference of two cubes, difference of two cubes, difference of two cubes, perfect square trinomials perfect square trinomials perfect square trinomials perfect square trinomials and general trinomials) and general trinomials) and general trinomials) and general trinomials) (M8AL-Ia-b-1) (M8AL-Ia-b-1) (M8AL-Ia-b-1) (M8AL-Ia-b-1) a. Factor polynomials with common monomial factor. b. Apply the theorems in proving inequalities in triangle. c. Appreciate the concept about factoring out the common factor in polynomials. a. Factor the difference of two squares . b. Solve equations by factoring the difference of two squares. c. Find pleasures in working with numbers. a. Find the factors of the 1. Identify a perfect square sum or difference of two trinomial. cubes. 2. Get the square of the b. Completely factor a numbers. polynomial involving the 3. Factor a perfect square sum and difference of two trinomial cubes. c. Find pleasures in working with numbers. II. CONTENT Factor of Polynomials With Common Monomial Factor(CMF) Factoring the Difference of Two Squares Factoring a Perfect Square Trinomial Factoring the Sum or Difference of Two Cubes III. LEARNING RESOURCES A. References 1. Teacher’s Guide pages 29-33 pages 34-35 pages 36-37 pages 38-39 2. Learner’s Materials pages 27-31 pages 32-33 pages 34-35 pages 36-38 3. Textbook Intermediate Algebra UBD pages 22-23 Mathematics Activity Sourcebook pages 22-23 Mathematics Activity Intermediate Algebra UBD Sourcebook pages 25- 26 pages 24-25 4. http://lmrds.deped.gov.ph. Additional Materials from Learning Resource (LR) portal http://lmrds.deped.gov.ph. http://lmrds.deped.gov.ph. B. Other Learning Resources http://lmrds.deped.gov.ph. Grade 8 LCTG by Dep Ed Cavite Mathematics 2016 laptop, LCD Grade 8 LCTG by Dep Ed Grade 8 LCTG by Dep Ed Grade 8 LCTG by Dep Ed Cavite Mathematics 2016 Cavite Mathematics 2016 Cavite Mathematics 2016 laptop, LCD laptop, LCD laptop, LCD 1. Asking the common physical features/ behavioural traits among siblings in the family. SECRET MESSAGE Find the square roots and solve the secret message. 4 = ___ 16 = ___ 16 = ___ 81 = ___ 49 = ___ 9 = ___ IV. PROCEDURES A. Reviewing previous lesson or presenting the new lesson Purpose Setting Activity So here are the formulas that summarize how to factor the sum and difference of two cubes. Find the square of the following: 1. 1 2. 4 3. 9 6. 36 7. 49 8. 81 2. What are the things common to each set of pictures? Study them carefully using 4. 16 9. a2 the following diagrams. 5. 25 10. x4 81 = ___ 25 = ___ 16 = ___ 100 = ___ 9 = ___ 36 = ___ 121= ___ 16 = ___ 25 = ___9 = ___ 144 = ___ 64 = ___ 81= ___ 289 = ___ 225 = ___ 49 =___ 9 = ___ 81 = ___ 25= ___ 16 =___ 100= ___ 9 =___ A 16 B 16 C 25 E 299 F 100 G 400 I 36 J 81 K 64 M 144 N 100 O 9 Q 49 R 900 S 121 U 24 V 9 W 81 Y 8 X 9 D 1000 H 4 L 81 P 64 T 4 X 225 Observations: •For the “sum” case, the binomial factor on the right side of the equation has a middle sign that is positive. •In addition to the “sum” case, the middle sign of the trinomial factor will always be opposite the middle sign of the given problem. Therefore, it is negative. •For the “difference” case, the binomial factor on the right side of the equation has a middle sign that is negative. •In addition to the “difference” case, the middle sign of the trinomial factor will always be opposite the middle sign of the given problem. Therefore, it is positive. Factoring the common Factoring the difference of Factoring the sum or Factoring a perfect square B. Establishing a monomial factor is the two squares is the reverse difference of two cubes is trinomial is the reverse purpose for the lesson reverse process of monomial process of the product of the reverse process of process of square o to polynomials. sum and difference of two product of binomial and binomial. a(b + c) = ab + ac (x + y)2 = x2 + 2xy + y2 terms. trinomial. 2 2 2 2 (x + y)(x – y) = x – y (x + y)(x – xy + y ) (x - y)2 = x2 - 2xy + y2 = x3 + y3 (x + y)(x2 + xy + y2) = x3 - y3 C. Presenting examples/ a. Factor xy +xz Get the CMF, x instances of the Divide xy + xz by x lesson Quotient: y + z Thus xy + xz = ( y + z) b. Factor 5n² + 15n Get the CMF, 5n Divide 5n² = 15 n by 5n Quotient: n + 3 Thus 5n² + 15n = 5n (n + 3) Factor 4y2 - 36y6 1: Factor x3 + 27 Study the trinomials and •There is a common factor Currently the their corresponding of 4y2 that can be factored problem is not written in the binomial factors. out first in this problem, to form that we want. Each 1. x2 + 10x + 25 = ( x + 5)2 make the problem easier. term must be written as 2. 49x2 – 42 + 9 4y2 (1 - 9y4) cube, that is, an expression = ( 7x – 3)2 4 •In the factor (1 - 9y ), 1 raised to a power of 3. The 3. 36 + 20 m + 16m2 and 9y4 are perfect squares term with variable x is okay = (6 + 4m)2 (their coefficients are but the 27 should be taken 4. 64x2 – 32xy + 4y2 perfect squares and their care of. Obviously we know = (8x – 2y)2 exponents are even that 27 = (3)(3)(3) = 33. numbers). Since Rewrite the original a. Relate the first term in subtraction is occurring problem as sum of two the trinomial to the first D. Discussing new concepts and practicing new skills #1 c. Factor 27y² + 9y -18 The CMF is 9 Divide 27y² + 9y -18 by 9 The quotient is 3y² + y -2 Thus 27y² + 9y -18 = 9 ( 3y² + y -2) between these squares, cubes, and then simplify. term in the binomial this expression is the Since this is the "sum" case, factors. difference of two squares. the binomial factor and b. Compare the second trinomial factor will have term in the trinomial positive and negative factor and the sum of the •What times itself will give middle signs, respectively. product of the inner 1? x3 + 27 = (x)3 + (3)3 terms and outer terms of 2 2 •What times itself will give = (x+3)[{x) –(x)(3)+(3) ] the binomials. 9y4 ? =(x+3)(x2-3x+9) c. Observe the third term in •The factors are (1 + 3y2) the trinomial and the 2 3 and (1 - 3y ). Example 2: Factor y - 8 product of the second •Answer: This is a case of terms in the binomials. 4y2 (1 + 3y2)(1 - 3y2) or difference of two cubes 4y2 (1 - 3y2) (1 + 3y2) since the number 8 can be written as a cube of a number, where 8 = (2)(2)(2) = 23. Apply the rule for difference of two cubes, and simplify. Since this is the "difference" case, the binomial factor and trinomial factor will have negative and positive middle signs, respectively. Question : What fruit is the main product of Tagaytay City? You will match the products in Column A with the factors in Column B to decode the answer. Factor each of the following: 1. c² - d² 2. 1 - a² 3. ( a + b )² - 4c² 4. 16x² - 4 5. a²b² - 144 Factor the following: 1. x3 – 8 2. 27x3 + 1 3. x3y6 – 64 4. m³ + 125 5. x³ + 343 Supply the missing term to make a true statement. 1. m2 + 12m + 36 = (m + ___)2 2. 16d2 – 24d + 9 = (4d – ___)2 3. a4b2 – 6abc + 9c2 = (a2b ___)2 4. 9n2 + 30nd + 25d2 = (____ 5d)2 5. 49g2 – 84g +36 = ( ______)2 E. Discussing new concepts and practicing new skills #2 Factor the following 1. a²bc + ab²c + abc² 2. 4m²n² - 4mn³ 3. 25a + 25b 4. 3x² + 9xy 5. 2x²y + 12xy F. Developing mastery (Leads to Formative Assessment 3) Factor the following: 1. 10x + 10y + 10z 2. bx + by + bz 3. 3x³ + 6x² + 9x 4. 10x + 5y –20z 5. 7a³ + 14a² + 21 G. Finding practical Factor the following Fill in the blanks to make the sides of each equation equivalent. 1. ( _____ ) ( x – 9) = x² -81 2. ( 20 + 4) ( _____ ) = 20² -4² 3. ( _____ ) (2a +3 ) = 4a² - 9 4. ( 6x²y + 3ab)(6x²y -3ab) = ( _____ ) - 9a²b² 5. ( 13 + x ) (13 – x) = _____ - x² Complete the factoring. 1. t3 - w3 =(t–w)( 2. m3 + n3 =(m+n)( 3. x3 + 8 = (x+2)( 4. y3 - 27 =(y–3)( 5. 8- v3 =(2–v)( Factorize the following by taking the difference of squares: 1. x2 – 100 2. a2 – 4 3. ab2 – 25 4. 36𝑥2 – 81 5. 54𝑥2 – 6y2 Factor the following. Factor each completely. Factor the following: a) x ³ + 125 1. 1. x2 – 5x + 25 b) a ³ + 64 2. 2. b2 -10b + 100 c) x ³ – 64 3. 36b2 – 12b + 1 d) u ³ + 8 4. 49p2 – 56p = 16 5. 49k2 – 28kp + 4p2 ) ) ) Factor the following trinomials. 1. x2 + 4x + 4 2. x2 - 18x + 81 3. 4a2 + 4a + 1 4. 25m2 – 30m + 9 5. 9p2 – 36p + 16 ) ) Directions. Find the cube Complete the perfect 1. 16a² + 12a applications of concepts and skills in 2. 12am + 6a²m 3. 72x² + 36xy – 27x daily living 4. 5a³ + a³b 5. 30a + 5ay - 25 az 1. 2. 3. 4. 5. 100a2 – 25b2 1 – 9a2 81x2 – 1 – 64a2 + 169 b2 x2 – 144 roots. Then, match each square trinomial and factor solution to the numbers at them. the bottom of the page. 1. ___ + 16x + 64 Write the corresponding 2. x2 - ___ + 49 letter in each blank to the 3. x2 + 4x + ___ question.In the survey, 4. x2 + ___ + 9y2 Best place for family picnic 5. ___ + 10k + 25 in Tagaytay City? No 1 2 3 4 27 512 343 216 C R G O 5 6 7 8 1728 8 1 729 P 2 1 1 9 10 11 1331 1000 219 I C V 12 0 0 13 64 E 14 125 N 12 11 3 5 9 10 7 8 6 13 4 Common Monomial Factor H. Making generalizations and To factor polynomial with abstractions about the common monomial factor, lesson expressed the given polynomial as a product of the common monomial factor and the quotient obtained when the given polynomial is divided by the common monomial factor. The factors of the 1. The sum of the cubes of difference of two squares two terms is equal to are the sum of the square the sum of the two terms roots of the first and multiplied by the sum second terms times the of the squares of these difference of their square terms minus the product roots. of these two terms. a³ + b³ *The factors of 𝑎2 − 𝑏2 = ( a + b ( a² - ab + b² ) =𝑎𝑟𝑒 ( 𝑎 + 𝑏 ) 𝑎𝑛𝑑 ( 𝑎 −𝑏 ). I. Evaluating learning Factorize the following by taking the difference of squares: 1. x2 – 9 2. a2 – 1 3. ab2 – 16 4. 16𝑥2 – 49 5. 54𝑥2 – 6y2 Factor the following: 1. 5x + 5y + 5z 2. ax + ay + az 3. 4x³ + 8x² + 12x 4. 6x + 18y – 9z 5. 3a³ + 6a² + 12 In factoring a perfect square trinomial, the following should be noted: 1. The factors are binomials with like terms wherein the terms are the square roots of the first and the last terms of the trinomial. 2. The sign connecting the 2. The difference of the terms of the binomial cubes of two terms is factors is the same as equal to the difference of the sign of the middle the two terms multiplied term of the trinomial. by the sum of the squares of these two terms plus the product of these two terms. a³ - b³ = ( a - b ( a² + ab + b² ) Supply the missing Factor the following: expression. 3. 1. x2 – 6x + 9 4. 2. b2 -12b + 36 1. 𝑚3 - 27 3. 4b2 – 4b + 1 = (m – 3) _________ 4. 49p2 – 56p = 16 2. 64 + 27𝑛3 5. 49k2 – 28kp + 4p2 = ____(16 – 12n + 9𝑛2 ) 3. _______ = ( 2p + 5q ) ( 4𝑝2 – 10pq + 25𝑞2 ) 4. 𝑥6 + 1000 = _____𝑥4 - 10𝑥2 + 100 ) J. Additional activities for A. Follow up application or Supply the missing term remediation 1. 3a + 3b = ____ (a + b) 2. bx + by + bz = _____ (x + y + z) 3. a²b - ab² = ab (_____ 4. 4x + 6y = ____(2x + 3y ) 5. m³ - m = ____(m² - 1) B. Study Factoring Polynomials 1. What is a common monomial factor? 2. How will you factor polynomial by grouping? Reference: G8 Mathematics Learner’s Module pages 45-46 V. REMARKS VI. REFLECTION 1. No.of learners who earned 80% on the formative assessment 2. No.of learners who require additional activities for Factorize the following by taking the difference of squares: 1. x2 – 9 2. a2 – 1 3. ab2 – 16 4. 16𝑥2 – 49 5. 54𝑥2 – 6y2 5. ________ = ( 6x – 7y ) ( 36𝑥2 + 42xy + 49𝑦2 ) Solve the following: Complete the perfect 1. The product of two square trinomial and factor consecutive even them. integers is 528. Find the 1. ___ + 16x + 64 value of each integer. 2. x2 - ___ + 49 3. x2 + 4x + ___ 4. x2 + ___ + 9y2 5. ___ + 10k + 25 remediation. 3. Did the remedial lessons work? No.of learners who have caught up with the lesson. 4. No.of learners who continue to require remediation 5. Which of my teaching strategies worked well? Why did these work? 6. What difficulties did I encounter which my principal or supervisor can help me solve? 7.