Explanation:
The general equation of a straight line graph is y = mx + c, where m is the gradient of the line and c is the y-intercept.
Gradient = (2 - (-18)) / (3 - (-2)) = 20/5 = 4.
So y = 4x + c.
When x = 3, y = 2. (Given in the question)
This means that 2 = 4(3) + c, hence c = -10.
The answer is y = 4x - 10.