Answer:
f(3) = -11
f(-5) = 37
Explanation:
f(x) = -6x + 7 
We want to find f(3) and f(-5) 
To do so we substitute the input with any x in the equation and evaluate.
f(3) = -6x + 7
==> substitute all x's with the input, 3 
f(3) = -6(3) + 7 
==> multiply -6 and 3 
f(3) = -18 + 7 
==> add -18 and 7 
f(3) = -11
f(-5) = -6x + 7
==> substitute all x's with the input -5
f(-5) = -6(-5) + 7 
==> multiply -6 and -5
f(-5) = 30 + 7
==> add 30 and 7 
f(-5) = 37