Answer :
Answer:
a. -28
b. 4
Step-by-step explanation:
f: x→ 5x-8
a. f(-4) = 5(-4) - 8 = -20 - 8. = -28
b. the value of x whose image is 12
To find the value of x ,we have to solve f(x) = 12
f(x) = 12
⇔ 5x-8 = 12
⇔ 5x = 12 + 8
⇔ 5x = 20
⇔ x = 20 ÷ 5 = 4