Two-step equations word problems. Please and thank you in advance!

Solve the system of equations. y= 2x y= x^2 - 15

If 25% of y is 30, what is 60% of y?

Which rule describes the composition of transformations that maps ajkl to aj"k"l"? ro. 900 o to, -2(x, y) to, -20 ro, 900(x, y) ro, 9000 t-2. o(x,y) t-2, 00 ro, 900(x, y)