Linear Equations in Two Unknowns: Worksheet 1 Name: ( ) F. Activity y 6 5 A (2, 4) 4 3 2 1 –5 –4 –3 –2 –1 0 –1 x 1 2 3 4 5 –2 –3 –4 –5 –6 In the figure above, let x and y be the x- and y-coordinates of A respectively. (a) Suggest FOUR possible relations between x and y. (b) (i) Choose either one of the above relations. Express it in the form y = … in the table given. (ii) Fill in the table the coordinates of some other points satisfying the relation. (iii) Plot these points in the above graph. (iv) What do we get if we plot ALL points satisfying the equation? 1 x y = __________ 2 4 (c) The collection of ALL the points satisfying the equation on the rectangular coordinate plane is called the graph of the equation. (i) Draw the graph of the equation. (ii) Suggest some points outside the range shown in the graph which: lie on the graph; do not lie on the graph. Discuss how you can tell whether these points lie on the graph or not. 2 Exercise 1.. The above figure shows the graph of y = 2x + 4. Which of the following points lie on the graph? (There may be more than one answer.) P(–1 , 3), Q(–2 , 0), R(1 , 6), S(–10 , – 24) Answers: (Write down the letter(s).) 2.. y 4 3 2 1 x –4 –3 –2 –1 O –1 1 2 3 4 5 –2 (a) The figure above shows the graph of an equation. Which of the following points lie on the straight line? (There may be more than one answer.) P(3 , 3), Q(1 , 2), R(0 , 2), S(5 , 2) Answers: 3 2. (b) Which of the following is the equation of the graph? A. y= 3 x 2 B. y= 5 x 3 C. y= 4 2x 3 D. y= 10 4 x 5 3.. Given that the equation of straight line L is x 2 y 2 0 , which of the following points lies on L ? A. (2 , 1) B. ( 2 , 1) C. D. (198 , 100) ( 198 , 100) 4.. Which of the following points DOES NOT lie on the straight line 2x + y + 4 = 0? A. (2 , – 8) B. ( 2 , 0) C. (0 , 4 ) D. (3, 10) END 4