# Math Help - Finding constants with difference q.

1. ## Finding constants with difference q.

Im having trouble with this one:

Let f(x)= -3x - 7. Then the expression

$[f(x+h)-f(x)]/h$

can be written in the form Ah+Bx+C, where A, B, and C are constants.

Find A, B, and C

Thank you!

2. Originally Posted by jtowery
Im having trouble with this one:

Let f(x)= -3x - 7. Then the expression

$[f(x+h)-f(x)]/h$

can be written in the form Ah+Bx+C, where A, B, and C are constants.

Find A, B, and C

Thank you!
The expression $[f(x+h)-f(x)]/h$ is the slope of the line.

f(x)=-3x-7 is linear, the graph of a straight line.

$\frac{y_2-y_1}{x_2-x_1}=[f(x+h)-f(x)]/h$

$[f(x+h)-f(x)]/h=\frac{-3(x+h)-7+3x+7}{h}=\frac{-3x-3h+3x}{h}=-3$

A=0, B=0, C=-3.

3. Awesome. I cannot thank you enough!