77//x-2 - 77//x+2 =4
77*(x+2) - 77*(x-2)//x^2-4 =4
77x+154-77x+154//x^2-4=4
308//x^2-4=4
308/4=x^2-4
77=x^2-4
77+4=x^2
x^2=81
x=9
77//x-2 - 77//x+2 =4
77*(x+2) - 77*(x-2)//x^2-4 =4
77x+154-77x+154//x^2-4=4
308//x^2-4=4
308/4=x^2-4
77=x^2-4
77+4=x^2
x^2=81
x=9