Page 135 - MAT KS3 Y8 Cambridge CheckPoint

13.2 Equations of the form y = mx + c

✦ Exercise 13.2 40 y

30
For questions 1 to 4, draw the graph on a copy of this grid.
20
1 a Copy and complete this table for y = 10x.
10
x −4 −3 −2 −1 0 1 2 3 4 –4 –3 –2 –1 0 1 2 3 4 x
y −40 −10 10 40 –10
–20
b Draw a graph of y = 10x. –30
–40
2 a Copy and complete this table for y = 5x − 20.
x −4 −2 0 2 4
y −40 −20

b Draw a graph of y = 5x − 20.
c Show that (20, 80) is on the line y = 5x − 20.

3 a Copy and complete this table for y = 15x − 5.

x −2 −1 0 1 2 3
y −20 10

b Draw a graph of y = 15x − 5.
c Is (5, 80) on the line y = 15x − 5? Give a reason for your answer.
4 a Copy and complete this table for y = 20 − 10x. x −2 −1 0 1 2 3 4
b Draw a graph of y = 20 − 10x. y
c (7, c) is on the line y = 20 − 10x. Find the value of c. 30 10 −20
d (−4, d) is on the line y = 20 − 10x. Find the value of d.

5 a Copy and complete this table x −20 −15 −10 −5 0 5 10 15 20
for y = 0.2x + 3. y
b Draw a graph of y = 0.2x + 3. Choose −1 7
suitable scales for the axes.
c (3, a) is on the line y = 0.2x + 3. Find the value of a.
6 a Copy and complete this table for y = 40x + 20.

x −3 −2 −1 0 1 2 3
y −20 60 140

b Draw a graph of y = 40x + 20. Choose suitable scales for the axes.
c Show that Anders is not correct.

(10, 420) and (−10, −420) are
both on the line y = 40x + 20.

7 The line y = 0.5x + 8 passes through (−10, a) and (−20, b). Find the values of a and b.
8 a Where does the line y = 5x − 10 cross the y-axis?
b Where does the line y = 5x − 10 cross the x-axis?

13 Graphs 133