Answer
$A=x^2-2x$.
Work Step by Step
The given area formula
$A=\frac{1}{2}h(b_1+b_2)$.
The height of the trapezoid $h=x-2$.
The lengths of the bases are
$b_1=x+2$ and $b_2=3x-2$.
Substitute all values into the formula.
$A=\frac{1}{2}(x-2)(x+2+3x-2)$
Simplify.
$A=\frac{1}{2}(x-2)(4x)$
$A=x(x-2)$
Use the distributive property.
$A=x^2-2x$.
