Question

A line that includes the points (7,f) and (3,-5) has a slope of 3. What is the value of f?

Answer 1

Slope: y change / x change

-5-f -5-f
----- = ------
3-7 -4

the numerator must be -12 because -4 x 3 = -12

what makes it -12?

-5-f=-12
-f=-7
f=-7

there you go!