Answer
$\frac{5}{2}x^2+2x+\frac{1}{2}$
Work Step by Step
The area $A$ is:
$A=\frac{1}{2}(2x+1-x)(2x+1-x)+x(2x+1)$
$A=\frac{1}{2}(x+1)(x+1)+2x^2+x$
$A=\frac{1}{2}(x^2+2x+1)+2x^2+x$
$A=\frac{1}{2}x^2+x+\frac{1}{2}+2x^2+x$
$A=\frac{5}{2}x^2+2x+\frac{1}{2}$
Thus, the expression of the area is:
$$\frac{5}{2}x^2+2x+\frac{1}{2}$$
