Answer:
10
Step-by-step explanation:
Step 1: Equation
f (x) = 3x - 20
Step 2: Given
x = 10
Step 3: Substitute
f (10) = 3 ( 10 ) - 20
Step 4: Solve
f (10) = 30 - 20
Step 5:
f (10) = 10
Hope This Helps :)
