X+287+888-8x+x(x+10-7x)=0

х + 287 + 888 -8х + х(х + 10 - 7х) = 01175 - 7х + х^2 + 10х - 7х^2 = 03х - 6х^2 = -1175-3 * (2х^2 - х) = -11752х^2 - х = 391[latex] frac{2}{3} [/latex]

x+287+888-8x+x^2+10x-7x^2=0x^2-7x^2+x-8x+10x+287+888=0-6x^2+3x+1175=0Д=3^2-4*(-6)*1175=9+28200=28209х1,2= (-3 +/-  корень квадр. из 28209)/(2*(-6))х1=-13.746279х2=14.246279