Question

f is a linear function such that f(-1)=2.5 and f(1)=-3 what is the value of f(4)

Answer 1

Dear student
The two points given are (-1,2.5) and (1,-3). use slope formula to find slope. (-3-2.5)/(1+1)=-5.5/2=m

use point slope formula to find equation of a line. y-y1 = m(x-x1)
so y-2.5 = $\frac{-5.5}{2}$(x+1)
y-2.5 = -2.75x+2.75
y = -2.75x+5.25

plug in 4 to find f(4)
so y = -2.75(4)+5.25 = -5.75
Regards