Question 180595
2t(x - 2t) = y(x - y)
2tx-4t^2=xy-y^2
2tx-xy=4t^2-y^2
x(2t-y)=4t^2-y^2
x=(4t^2-y^2)/(2t-y) 
x=(2t+y)(2t-y)/(2t-y)
x=2t+y ans.