\(x^4+81\)

\(=x^4+3^4\)

\(=\left(x^2+3^2\right)^2-2x^23^2\)

\(=\left(x^2+\sqrt{2}x3+3^2\right)\left(x^2-\sqrt{2}x3+3^2\right)\)

nguồn gg

\(x^4+81\)

\(=x^4+18x^2+81-18x^2\)

\(=\left(x^2+9\right)^2-18x^2\)

\(=\left(x^2-3\sqrt{2}x+9\right)\left(x^2+3\sqrt{2}x+9\right)\)

x^4+4=x^4 + 4x^2 +4 - 4x^2=(x^2)^2+ 2.x^2.2+2^2 - (2x)^2 = (x^2+2)-(2x)^2 =(x^2+2-2x)(2^2+2-2x)

\(x^4+4=x^4+4x^2+4-4x^2\)

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

                  \(=\left(x^2+2-2x\right)\left(x^2+2+2x\right)\)

x^4+x^2+1 = (x^4+2x^2+1)-x^2 = (x^2+1)^2-x^2 = (x^2-x+1).(x^2+x+1)

k mk nha

bạn ơi bạn chưa bớt 2x^2 kìa

x⁵-x⁴-1=x⁵-x³-x²-x⁴+x²+x+x³-x-1

=x².(x³-x-1)-x.(x³-x-1)+(x³-x-1)

=(x³-x-1)(x²-x+1)

x^4+x^2+1 = (x^4+2x^2+1)-x^2 = (x^2+1)^2-x^2 = (x^2-x+1).(x^2+x+1)

k mk nha

\(x^4+1\)

\(=x^4+2x^2+1-2x^2\)

\(=\left(x^2+1\right)^2-2x^2\)

\(=\left(x^2-\sqrt{2}x+1\right)\left(x^2+\sqrt{2}x+1\right)\)

x⁴ + 64

= x⁴ + 16x² + 64 - 16x²

= (x² + 8)² - (4x)²

= (x² - 4x + 8)(x² + 4x + 8)

4x⁴ + 1

= 4x⁴ + 4x² + 1 - 4x²

= (2x² + 1) - (2x)²

= (2x² - 2x + 1)(2x² + 2x + 1)

64x⁴ + 1

= 64x⁴ + 16x² + 1 - 16x²

= (8x² + 1)² - (4x)²

= (8x² - 4x + 1)(8x² + 4x + 1)

x³-3x²-4=

\(x^8+x^4+1\)

\(=x^4.\left(x^4+1\right)+\left(x^4+1\right)-x^4\)

\(=\left(x^4+1\right).\left(x^4+1\right)-\left(x^2\right)^2\)

\(=\left(x^4+1\right)^2-\left(x^2\right)^2\)

\(=\left(x^4+1-x^2\right).\left(x^4+1+x^2\right)\)