\(A=\left(x-3\right)\left(x+2\right)-x\left(x+1\right)\)
\(=x^2+2x-3x-6-x^2-x=-6x-6=-6\left(x-1\right)\)
\(A=\left(x-3\right).\left(x+2\right)-x.\left(x+1\right)\)
\(A=x^2+2x-2x-6-x^2-x\)
\(A=\left(x^2-x^2\right)+\left(2x-2x-x\right)-6\)
\(A=-\left(x+6\right)\)
Chúc bạn học tốt!!!
Mình làm lại chỗ kia mình nhầm!
\(A=\left(x-3\right).\left(x+2\right)-x.\left(x+1\right)\)
\(A=x^2+2x-3x-6-x^2-x\)
\(A=\left(x^2-x^2\right)+\left(2x-3x-x\right)-6\)
\(A=-2x-6=-2.\left(x+3\right)\)
Chúc bạn học tốt!!!
