=(x^2+x)^2-2(x^2+x)+1-16
=(x^2+x-1)^2-4^2
=(x^2+x-1-4)(x^2+x-1+4)
=(x^2+x-5)(x^2+x+3)
\(\left(x^2+x\right)^2-2\left(x^2+x\right)-15\)
\(=\left(x^2+x\right)^2-2\left(x^2+x\right)+1-16\)
\(=\left(x^2+x+1\right)^2-4^2\)
\(=\left(x^2+x+1+4\right)\left(x^2+x+1-4\right)\)
\(=\left(x^2+x+5\right)\left(x^2+x-3\right)\)
Sorry , bạn nha : Sửa lại :
\(\left(x^2+x\right)^2-2\left(x^2+x\right)-15\)
\(=\left(x^2+x\right)^2-2\left(x^2+x\right)+1-16\)
\(=\left(x^2+x-1\right)^2-4^2\)
\(=\left(x^2+x-1+4\right)\left(x^2+x-1-4\right)\)
\(=\left(x^2+x+3\right)\left(x^2+x-5\right)\)