Câu 11:
a: =x^2-x-5x+5
=(x-1)(x-5)
b: \(=x^5+x^4+x^3-x^4-x^3-x^2+x^2+x+1\)
=(x^2+x+1)(x^3-x^2+1)
c: \(=\left(x^2+7x+10\right)\left(x^2+7x+12\right)-24\)
\(=\left(x^2+7x\right)^2+22\left(x^2+7x\right)+96\)
=(x^2+7x+6)(x^2+7x+16)
=(x+1)(x+6)(x^2+7x+16)