1. x2-4x-y2+4
2. (x-y)2-(x+y)2
Phan tich da thuc thanh nhan tu
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
x^3 - 2x^2y + xy^2
phan tich da thuc thanh nhan tu a
\(=x\left(x^2-2xy+y^2\right)=x\left(x-y\right)^2\)
phan tich da thuc sau thanh nhan tu:
a) (3x-2)(4x-3)-(2-3x)(x-1)-2(3x-2)(x+1)
b) x^2(y-z)+y^2(z-x)+z^2(x-y)
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
1 Phan tich da thuc thanh nhan tu
b) 4x(x+y)(x+y+z)(x+z) +y2z2 ( phân tích thành số chính phương)
4x(x+y)(x+y+z)(x+z)+(yz)^2
=(2x(x+y+z))(2(x+y)(x+z)+(yz)^2
=(2x^2+2xy+2xz)(2x^2+2xy+2xz+2yz)+(yz)^2
Đặt t=C
=(t-yz)(t+yz)-(yz)^2
=t^2-(yz)^2+(yz)^2=t^2=(2x^2+2xy+2xz+yz)^2
=
cam on ban nhung mk lam xong roi
phan tich da thuc thanh nhan tu 4x^2 - y ^2+8(y-2)
\(4x^2-y^2+8\left(y-2\right)=4x^2-y^2+8y-16=4x^2-\left(y-4\right)^2=\left(2x-y+4\right)\left(2x+y-4\right)\)
phan tich da thuc sau thanh nhan tu (bang cach dat nhan tu chung)
(4x-y)(a+b)(4x-y)(c-1)
\((4x-y)(a+b)(4x-y)(c-1)\)
\(=\left(4x-y\right)\left(4x-y\right)=\left(4x-y\right)^{1+1}=\left(4y-2\right)^2\)
\(=\left(a+b\right)\left(4x-y\right)^2\left(c-1\right)\)
(4x-y)(a+b)(4x-y)(c-1)
= ( 4x - y ) ( 4x - y ) = ( 4x - y ) 1 + 1 = ( 4y - 2 ) 2
= (a + b ) ( 4x - y )2 ( c - 1 )
Bài giải :
(4x-y)(a+b)(4x-y)(c-1)
= ( 4x - y ) ( 4x - y ) = ( 4x - y ) 1 + 1
= ( 4y - 2 ) 2
= (a + b ) ( 4x - y )2 ( c - 1 )
Phan tich da thuc thanh nhan tu
(xy-1)^2 -x^2-y^2
phan tich da thuc thanh nhan tu
x^2-y^2+2x+1
Lưu ý rằng ba điều kiện đầu tiên yếu tố như (x + 1) ^ 2, do đó chúng ta có:
x^2 + 2x + 1 - y^2 = (x + 1)^2 - y^2.
(x + 1)^2 - y^2 = [(x + 1) + y][(x + 1) - y], từ a^2 - b^2 = (a + b)(a - b)
= (x + y + 1)(x - y + 1).