CPM Homework Help : GC Problem 3-100

The area of the rectangle shown at right is $40$ square units. Write and solve an equation to find $x$ . Then find the dimensions of the rectangle.

left edge top $+5$

left edge bottom $x$

bottom edge left $x$

bottom edge right $+2$

Hint:

Complete the multiplication in the generic rectangle. The sum of the small rectangles is $40$ square units.