Timed test, would really appreciate ! < 3

Solve the following pair of equations for x and y: ax/b_ by /a= a +b; ax - by = 2ab

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

Given the net of the rectangular prism, what is its surface area?