8x^2-2x-11
=8(x^2-1/4x)-11
=8(x^2-1/4x+(1/8)^2-(1/8)^2)-11
=8(x^2-1/4x+(1/8)^2)-1/8-11
=8(x-1/8)^2-89/8
=8((x-1/8)^2-89/64)
=8((x-1/8)+√89/8)((x-1/8)-√89/8)
=8(x+(√89-1)/8)(x-(√89+1)/8)
=1/8(8x+(√89-1))(8x-(√89+1))
8x^2-2x-11
=8(x^2-1/4x)-11
=8(x^2-1/4x+(1/8)^2-(1/8)^2)-11
=8(x^2-1/4x+(1/8)^2)-1/8-11
=8(x-1/8)^2-89/8
=8((x-1/8)^2-89/64)
=8((x-1/8)+√89/8)((x-1/8)-√89/8)
=8(x+(√89-1)/8)(x-(√89+1)/8)
=1/8(8x+(√89-1))(8x-(√89+1))