50% of the tickets sold at a water park were child tickets. If the park sold 86 tickets in all, how many child tickets did it sell

Right ∆abc has coordinates a(-7, 3), b( -7, 10), and c(-1, 3). the triangle is reflected over the x - axis and then reflected again over the y - axis to create ∆a'b'c'. which are the coordinates of vertex a'?