Yr 11 MCAT Algebra Practice 3 – based on NCEA externals 2009 and 2010 1. Jonathan found this equation… 4(a2)n x 3a4 = 12a16 What is the value of n? 2. Factorise 3. Solve these equations… a) a/ 3 a2 6. Solve for a… a) (4a – 5)(a + 2) = 0 + 7a – 60 –4=5 b) 3a + 5 = 3 – 5a c) (1 – 2a)(a + 3) = 0 4. Solve this inequation… 5a – 8 > 12 5. Make r the subject of this formula A = 4πr2 b) 4(a + 3) = 11 c) 4a – 7 = 8 + 2a 7. Find the whole numbers that can replace a, b and c so that this equation is true… x2 + ax – 8 = (x + 8)(x + c) 11. if 8a9 = 2a4 what is n =? 4an 12. Expand and simplify… (a + 5)(a – 7) = 13. Pam sends Christmas cards to her friends. Stamps cost 50 cents for each. Cards cost $2.75 for each. Pam spends a total of $68.25. She writes this equation 0.50f + 2.75f = 68.25 How many friends has Pam got? 8. Two square fields are side by side. They are the same length but one is 3m wider. Together they have an area of 860m2. Calculate the value of a 14. Anne was told that one factor of a2 + 48a – 100 is a – 2. What is the other factor? 15. Simplify 2a + 4a = 3 5 a 16. Solve for both a and b… a 9. Solve a 3 a2 – 10a – 39 = 0 10. Expand and simplify… (2a + 3)2 = 3a + 8b = 79 and a=b+8 Yr 11 MCAT Algebra Practice 3 – based on NCEA externals 2008, 2009 and 2010 1. Jonathan found this equation… 4(a2)n x 3a4 = 12a16 What is the value of n? 2. 3. = 4a2n x 3a4 = 12a2n + 4 so 2n + 4 = 16 2n = 12 n=6 Factorise a2 + 7a – 60 (a + 12)(a - 5) a/ b) c) 3 –4=5 a/ 3 =9 a = 27 3a + 5 = 3 – 5a 3a + 5a = 3 - 5 8a = -2 c) 4(a + 3) = 11 a + 3 = 2.75 a = -0.75 4a – 7 = 8 + 2a 4a – 2a = 8 + 7 2a = 15 a = 7.5 What multiplies to – 8? a = -1/4 1/ -3 a is ___ 2 or ___ 4. Solve this inequation… 5a – 8 > 12 5a > 20 a>4 5. Make r the subject of this formula A = 4πr2 -1x8 1x-8 -2x4 2x-4 because a is positive we can eliminate… therefore a = 7or2, b/c = -1or-2, 8or4 8. Two square fields are side by side. They are the same length but one is 3m wider. Together they have an area of 860m2. Calculate the value of a (1 – 2a)(a + 3) = 0 4πr2 = A r2 = A/4π r = ± √(A/4π) b) 5/ -2 a is ___ 4 or ___ 7. Find the whole numbers that can replace a, b and c so that this equation is true… x2 + ax – 8 = (x + b)(x + c) Solve these equations… a) 6. Solve for a… a) (4a – 5)(a + 2) = 0 a 11. if 8a9 = 2a4 what is n =? 4an n=5 12. Expand and simplify… (a + 5)(a – 7) = a2 - 7a + 5a - 35 = a2 – 2a – 35 13. Pam sends Christmas cards to her friends. Stamps cost 50 cents for each. Cards cost $2.75 for each. Pam spends a total of $68.25. She writes this equation 0.50f + 2.75f = 68.25 How many friends has Pam got? 3.25f = 68.25 f = 21 14. Anne was told that one factor of a2 + 48a – 100 is a – 2. What is the other factor? what x – 2 is -100? 50 base x height (a+a+3) x a so the other factor is (a + 50) (2a+3) x a 15. Simplify 2a + 4a = 10a + 12a 2a2+3a 15 15 =22a 3 5 2a2 + 3a = 860 15 a a 3 2 + 3a – 860 = 0 2a 16. Solve for both a and b… (2a + 43)(a - 20) = 0 20 a is-21.5 ___ or ___ area = area = area = area = 9. Solve a2 – 10a – 39 = 0 (a + 3 )(a- 13) 10. Expand and simplify… (2a + 3)2 = (2a+3)(2a+3) =4a2+12a+9 3a + 8b = 79 sub b + 8 in and 3(b+8) + 8b = 79 3b + 24 + 8b = 79 11b = 55 a=b+8 b=5 a=5+8 a = 13