Exercise 1 Page 537

We are asked to find the length of RS in the given trapezoid.

Recall that if a quadrilateral is a trapezoid, then the length of the midsegment is half the sum of the lengths of the bases. RS= 1/2 (MN + PO) We can substitute the given lengths of these segments into this equation. 9x - 1=1/2 (( 10x+3)+( 4x + 7)) Let's solve this equation to find x.

Now that we found x, we can find RS by substituting x=3 into the given expression, 9x - 1. RS= 9(3) - 1 ⇔ RS = 26 This corresponds to option D.