phan tich da thuc thanh nhan tu
xm+2 - xm
phan tich da thuc thanh nhan tu
x^2-x-y^2-y
x^2-2xy+y^2-z^2
bai 32 va 33 sbt
lop 8 bai phan tich da thuc thanh nhan tu bang cach nhom hang tu
Ta có
a, x2-x-y2-y
=x2-y2-(x+y)
=(x-y)(x+y) - (x+y)
=(x+y)(x-y-1)
b, x2-2xy+y2-z2
=(x-y)2-z2
=(x-y-z)(x-y+z)
con bai 32, 33 neu ban tra loi duoc minh h them
Phan tich da da thuc thanh nhan phan tu
(x^2+x+1)(x^2+x+2)-12
\(=\left(x^2+x\right)^2+3\left(x^2+x\right)+2-12\)
\(=\left(x^2+x\right)^2+3\left(x^2+x\right)-10\)
\(=\left(x^2+x+5\right)\left(x^2+x-2\right)\)
\(=\left(x^2+x+5\right)\left(x+2\right)\left(x-1\right)\)
Phan tich da thuc thanh nhan tu :x^2+7x-15
x^2 + 7x -15
= x^2 + 7x +12,25 -27,25
= (x+3,5)^2 - 27, 25
= ( x+3,5 - \(\sqrt{27,25}\))(x+3,5+\(\sqrt{27,25}\))
4x^2-36x+56 phan tich da thuc thanh nhan tu
4x2 - 36x + 56
= 4x2 - 28x - 8x + 56
= ( 4x2 - 28x ) - ( 8x - 56 )
= 4x( x - 7 ) - 8( x - 7 )
= ( x - 7 )( 4x - 8 )
= 4( x - 7 )( x - 2 )
x^2-4+4xy-8y. Phan tich da thuc thanh nhan tu
x^2-4+4xy-8y=x^2+4xy+4y^2-4y^2-8y-4=(x+2y)^2-(2y+2)^2=(x+2y-2y+2)(x+2y+2y-2)=(x+2)(x+4y-2)
3a + 3b - a^2-ab phan tich da thuc thanh nhan tu
\(=\left(3a-a^2\right)-\left(3b-ab\right)=\left(a-b\right)\left(3-a\right)\)
3a+3b-a2-ab
= 3a - a2 + 3b - ab
= a( 3-a ) +b( 3- a)
= ( a+b)(3 - a )
3a + 3b - a2 - ab
= 3a - a2 + 3b - ab
= a( 3 - a ) + b( 3 - a )
= ( a + b )( 3 - a )
phan tich da thuc thanh nhan tu: 4x^4-32x^2+1
4x^4 - 32x^2 +1 = 4x^4 + 4x^2 +1 - 36x^2 = (2x^2 + 1)^2 - 36x^2 = (2x^2 - 6x + 1)(2x^2 + 6x + 1)
4 x4 - 32 x2 + 1
= ( 2 x2 )2 - 2 . 2x2. 8 + 64 - 63
= ( 2 x2 - 8 )2 - 63
= ( 2x2 - 8 + √63 ) ( 2x2 - 8 - √63 )
Xong
phan tich da thuc thanh nhan tu 4x^2-y^2+8(y-2)
=4x2-y2+8y-16
=4x2-(y2 - 8y+16)
=4x2-(y-4)2
=(2x+y-4)(2x-y+4)
4x2-y2+8(y-2)
=4x2-y2+8.y-8.2
=4x2-y2+8y-16
phan tich da thuc thanh nhan tu 1-3x-x^3+3x^2
\(1-3x-x^3+3x^2\)\(=\left(1-x^3\right)+\left(3x^2-3x\right)\)
\(=\left(1-x\right)\left(x^2+x+1\right)+3x\left(x-1\right)\)
\(=\left(x-1\right)\left(3x-x^2-x-1\right)=\left(x-1\right)\left(2x-x^2-1\right)\)
phan tich da thuc thanh nhan tu x2-3x+18