X+287+888-8x+x(x+10-7x)=0
Х + 287 + 888 -8х + х(х + 10 - 7х) = 0 1175 - 7х + х^2 + 10х - 7х^2 = 0 3х - 6х^2 = -1175 -3 * (2х^2 - х) = -1175 2х^2 - х = 391