I need help with a word problem

Question

Assume that g(x) is a linear function. Knowing that g(-2)= -1 and g(-4)= 3, find the algebraic formula that corresponds to these statements.

Answer 1

Slope = (-1 - 3)/(-2 - (-4)) = -4/2 = -2

 

Pick one point.

 

-1 = -2(-2) + b

-1 = 4 + b

b = -5

 

y = -2x - 5 or 2x + y = -5

Answer 2

1) determine the slope, (-1 - 3) / (-2 -(-4)), or -4 / 2, or -2

2) substitute into slope intercept form: y = -2x + b

3) now substitute either pair to determine b.