Which expression is equivalent to 1/3b - 7

What is x and y (use substitution? ) 5x+3y=38 and y=3x+8?

Secant ac and bd intersect at point e inside f what is the measure of aed if measurements cd equals 30 a b is 50 and cb is 170

Given: △acm, m∠c=90°, cp ⊥ am , ac: cm=3: 4, mp-ap=1. find am.