Toán tìm x biết: (x+2)^3+x(3x+1)^2-4x(1+2x)(2x-1)=-6 18/07/2021 By Remi tìm x biết: (x+2)^3+x(3x+1)^2-4x(1+2x)(2x-1)=-6
(x+2)^3+x(3x+1)^2-4x(1+2x)(2x-1)=-6 x^3+6x^2+12x+8+x(9x^2+6x+1)-(4x+8x^2)(2x-1)=-6 x^3+6x^2+12x+8+9x^3+6x^2+x-8x^2+4x-16x^3+8x^2=-6 -6x^3+12x^2+17x+8=-6 Trả lời
(x+2)^3+x(3x+1)^2-4x(1+2x)(2x-1)=-6
x^3+6x^2+12x+8+x(9x^2+6x+1)-(4x+8x^2)(2x-1)=-6
x^3+6x^2+12x+8+9x^3+6x^2+x-8x^2+4x-16x^3+8x^2=-6
-6x^3+12x^2+17x+8=-6