Answer:
expression 3
Step-by-step explanation:
Using the formula for calculating the area
with h = 2x - 4 = 2(x - 2), [tex]b_{1}[/tex] = 7 and [tex]b_{2}[/tex] = 2x + 12
A = [tex]\frac{1}{2}[/tex] × 2(x - 2)(7 + 2x + 12)
= (x - 2)(2x + 19) ← expand factors using FOIL
= 2x² + 19x - 4x - 38
= 2x² + 15x - 38 → 3
