\(x^4+x^3-4x^2+x+1\)

\(=x^4+3x^3+x^2-2x^3-6x^2-2x+x^2+3x+1\)

\(=x^2\left(x^2+3x+1\right)-2x\left(x^2+3x+1\right)+\left(x^2+3x+1\right)\)

\(=\left(x^2-2x+1\right)\left(x^2+3x+1\right)\)

\(=\left(x-1\right)^2\left(x^2+3x+1\right)\)

bắt quả tang nha

\((x-3y)^2-2(x-3y)(x+3y)+(x+3y)^2\)

\(=(x-3y-x-3y)^2\)

=\((-6y)^2\)

\(=36y^2\)

5x( x - y ) + 12x - 12y 

= 5x( x - y ) + 12( x - y )

= ( x - y )( 5x + 12 )

x² + 2xy - 9 + y²

= ( x² + 2xy + y² ) - 9

= ( x + y )² - 3²

= ( x + y - 3 )( x + y + 3 )

\(5x\left(x-y\right)+12x-12y\)

\(=5x\left(x-y\right)+12\left(x-y\right)\)

\(=\left(x-y\right)\left(5x+12\right)\)

\(x^2+2xy-9+y^2\)

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

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

\(=\left(x+y-3\right)\left(x+y+3\right)\)

Bài làm 

a, \(5x\left(x-y\right)+12x-12y=5x\left(x-y\right)+12\left(x-y\right)=\left(5x+12\right)\left(x-y\right)\)

b, \(x^2+2xy-9+y^2=\left(x+y\right)^2-9=\left(x+y-3\right)\left(x+y+3\right)\)

2m²+10m+8= 2x(m^2+5m+4)
bt mỗi 1 câu...

a⁴ + 64 = (a⁴ + 16a² + 64) - 16a² = (a + 8)² - 16a² = (a + 8 + 4a) (a + 8 - 4a)

xin lỗi mk mj hc lp 7

=\(a\left(a^3+3.a^2.2b+3.a.4b^2+8b^3\right)-b\left(8a^3+3.4a^2.b+3.2a.b^2+b^3\right)\)

\(=a^4+6a^3b+12a^2b^2+8ab^3-8a^3b-12a^2b^2-6ab^3-b^4\)

\(=a^4-2a^3b+2ab^3-b^4=\left(a^4-b^4\right)-2ab\left(a^2-b^2\right)\)

\(=\left(a^2-b^2\right)\left(a^2+b^2\right)-2ab\left(a^2-b^2\right)\)

\(=\left(a^2-b^2\right)\left(a^2-2ab+b^2\right)=\left(a-b\right)\left(a+b\right)\left(a-b\right)^2\)

\(=\left(a-b\right)^3\left(a+b\right)\)

= a( a³ + 6a²b + 12ab² + 8b³ ) - b( 8a³ + 12a²b + 6ab² + b³)

= a⁴ + 6a³b +12a²b² + 8ab³ - 8a³b - 12a²b² - 6ab³ - b⁴

= a⁴ - 2a³b + 2ab³ -b⁴

= (a² + b²) (a² - b²) - 2ab² (a - b)

= (a² + b²) (a + b) ( a - b )- 2ab ( a - b )

= ( a - b) ( (a² + b²)( a + b )- 2ab)  

-(b-a)³*(b+a)

#thang: cho mk xin cach giai

B