Answer:
option D is correct
The value of x is 2
Step-by-step explanation:
Given the function: f(x) = 2(x+10)
if f(x) = 24 then solve for x;
Distributive property of multiplication states that when a number is multiplied by the sum of two numbers, then the first number can be distributed to both of those numbers and multiplied by each of them separately.
i,e 
f(x) = 2(x+10)
Applying distributive property we have;
= 2x+20
Now, substitute the value of f(x) = 24 to solve for x;

Subtraction property of equality states that you subtract the same number to both sides of an equation.
Subtract 20 to both sides of an equation, we get
24-20 = 2x+20-20
Simplify:
4 = 2x
Division property of equality states that you divide the same number to both sides of an equation.
Divide both sides by 2 we get

Simplify:
x =2
therefore, the value of x is 2.