parmenides51 14.10.2017 22:20 Find all the positive integers $x$ and $y$ that satisfy the equation $x(x - y) = 8y - 7$
GRCMIRACLES 05.01.2018 09:16 y={x^2+7}/{x+8} y=x-8+{71/x+8} 71/x+8 must be integer =>x+8=1,71 x=63,as x is positive x+8 cant be 1 =>x=63,y=56 is the only positive solution
Night_Witch123 10.05.2019 01:36 $$x(x-y)=8y-7 \implies x^2-xy-8y+7=0 \implies y^2+32y-28=(y+16)^2-284=k^2 \implies y=56 \implies x=63$$