Question

The line y = mx + c passes through the points (-2, 1) and (4,4).

Write down a pair of simultaneous equations involving m and c.
Solve the simultaneous equations.

Answer 1

Explanation:

Insert x for -2 & 4 and y for 1 & 4

1=-2m+c, 4=4m+c

solve the equation, m=1/2, c=2

Answer 2

y = 1/2m + 2

Explanation:

1 = -2m + c (1)

4 = 4m + c (2)

2 = -4m + 2c (1*)

(1*) + (2) = 6 = 3c

c = 2

y = mx + 2

4 = 4m + 2

2 = 4m

m = 1/2

so y = 1/2m + 2