1) \(x^4+64\)
\(=x^4+64+16x^2-16x^2\)
\(=\left(x^2\right)^2+2.x^2.8+8^2-16x^2\)
\(=\left(x^2+8\right)^2-\left(4x\right)^2\)
\(=\left(x^2+8-4x\right)\left(x^2+8+4x\right)\)
\(1,x^4+64\)
\(=x^4+64+16x^2-16x^2\)
\(=\left(x^4+4x^2+64\right)-4x^2\)
\(=\left[\left(x^2\right)^2+2.x^2.8+8^2\right]-\left(2x\right)^2\)
\(=\left(x^2+8\right)^2-\left(2x\right)^2\)
\(=\left(x^2+8-2x\right)\left(x^2+8+2x\right)\)
\(2,x^3+2x^2+5x+4\)
\(=x^3+x^2+x^2+4x+x+4\)
\(=\left(x^3+x^2+4x\right)+\left(x^2+x+4\right)\)
\(=x\left(x^2+x+4\right)+\left(x^2+x+4\right)\)
\(=\left(x^2+x+4\right)\left(x+1\right)\)
c,đề sai( mk nghĩ vậy thôi ,tại mk lm ko ra ,còn nếu đề đúng r thì cho mk xin lỗi nhé )