Please help solve this

Question

Given f(x)=x^2-2x, find the equation of the secant line passing through (-4,f(-4)) and (1,f(1))

Answer 1

f(-4) = 16+8= 24

f(1) = 1-2 = -1

the two points are (-4,24) and (1,-1)

the line through those two points has slope = (24+1)/(-4-1) = 25/-5 = -5

the equation of the secant line is:

y= -5x + b, calculate b by plugging in either point

-1 = -5x + b

b = 4

y=-5x +4 or

5x+y = 4