A trapezoid has an area of 20 cm2 and a height z cm. The lengths of the parallel sides are (2z + 3) cm and (6z - 1) cm. Find the height, z, of the trapezoid. In your final answer, include all of the formulas and calculations necessary.

Area of a trapezoid = ½ (a + b) h, where a and b are the lengths of the parallel sides and h is its height.

From your information 20 = ½ (2z + 3 + 6z - 1) z = ½ (8z + 2) z = z (4z + 1)

Solve 20 = 4z² + z which is 0 = 4z² + z - 20 using the quadratic formula