(x2 - 3)2 + 16
= (x2-3)2 + 2.4(x2-3) + 42 - 8.(x2-3)
= (x2-3+4)2 - 8.(x2-3)
\(=\left(x^2+1\right)^2-\left(\sqrt{8.\left(x^2-3\right)}\right)^2.\)
\(=\left(x^2+1-\sqrt{8.\left(x^2-3\right)}\right).\left(x^2+1+\sqrt{8.\left(x^2-3\right)}\right)\)
CÔNG CHÚA ÔRI sai rồi nhé bạn!
\(\left(x^2-3\right)^2+16=x^4-6x^2+3^2+16=x^4-6x^2+25\)
\(=x^4-4x^3+5x^2+4x^3-16x^2+20x+5x^2-20x+25\)
\(=x^2\left(x^2-4x+5\right)+4x\left(x^2-4x+5\right)+5\left(x^2-4x+5\right)\)
\(=\left(x^2-4x+5\right)\left(x^2+4x+5\right)\)