Here two areas are equal: That of the square equals that of the rectangle.
Let s represent the side length of the square. Then the area of the square is s^2.
The length of the rect. is 2s+5, and the width of the rect. is s-6.
"A square and rectangle have equal areas."
Thus, s^2 = (2s+5)(s-6), or s^2 = 2s^2 - 12s + 5s - 30
Simplifying, 0 = s^2 - 7s - 30. This factors to 0 = (s-10)(s+3).
Thus, s may be either 10 or -3. Lengths are not negative, so omit the -3. The side of the square, s, is 10 units.
Then the width of the rect. is s-6 = 4, and the length of the rect. is 2s+5, or 2(10)+5, or 25.
