Question

hu hu ai giải giúp mik đi đang cần gắp phân tích đa thức thành nhân tử

(x+2)(x+3)(x+4)(x+5)-24

Answer 1

\(=\left(\left(x+2\right)\left(x+5\right)\right)\left(\left(x+3\right)\left(x+4\right)\right)-24\)

\(=\left(x^2+7x+10\right)\left(x^2+7x+12\right)-24\)

Đặt \(x^2+7x+10=y\)ta có:

    \(y\left(y+2\right)-24\)

\(=y^2+2y-24\)

\(=y^2-4y+6y-24\)

\(=y\left(y-4\right)+6\left(y-4\right)\)

\(=\left(y-4\right)\left(y+6\right)\)

\(=\left(x^2+7x+10-4\right)\left(x^2+7x+10+6\right)\)

\(=\left(x^2+7x+6\right)\left(x^2+7x+16\right)\)

\(=\left(x^2+x+6x+6\right)\left(x^2+7x+16\right)\)

\(=\left(x\left(x+1\right)+6\left(x+1\right)\right)\left(x^2+7x+16\right)\)

\(=\left(x+1\right)\left(x+6\right)\left(x^2+7x+16\right)\)