Find x I guess. (I don't know what to say)

x = 28

Step-by-step explanation:

1. ∠AOD and ∠COB are equivalent because they're vertical angles (opposite pair of angles that are formed from the intersection of two lines). That means that 3x + x + x + 12 = 152.

2. (Solving 3x + x + x + 12 = 152)

Step 1: Simplify both sides of the equation.

Step 2: Subtract 12 from both sides.

Step 3: Divide both sides by 5.

Step 4: Check if solution is correct.

Therefore, x = 28.

(f+g)(x) = 3^x+10x+4x-2

      =3^x +14x-2

choice b