Can someone help me please :)

Which expression is equivalent to7_/x^2 ÷ 5_/y^3? assume y# 0

The coordinates r(1, -3), s(3, -1) t(5, -7) form what type of polygon? a right triangle an acute triangle an equilateral triangle an obtuse triangle

y=2x−1 5x−4y=1 is (1,1)(1,1) a solution of the system?