Question

The perimeter of a trapezoid is 39a-7. Three sides have the following length:9a,5a+1, and 17a-6. What is the length of the forth side?

Answer 1

Then, it would be:

39a-7 = 9a+5a+1+17a-6+x

39a-7 = 31a-5+x

x= 39a-31a-7+5

x = 8a-2