Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a) 3a2-6ab+3b2-12c2
=3.(a2-2ab+b2-4c2)
=3.[(a-b)2-4c2]
=3.(a-b-2c)(a-b+2c)
a)\(81x^2-6yz-9y^2-z^2\)
\(=81x^2-\left(z-3y\right)^2\)
\(=\left(9x-z+3y\right)\left(9x+z-3y\right)\)
b)\(x^2y-x^3-9y+9x\)
\(=x^2\left(y-x\right)-9\left(y-x\right)\)
\(=\left(y-x\right)\left(x-3\right)\left(x+3\right)\)
c)\(3a^2-6ab+3b^2-12c^2\)
\(=3\left(a^2-2ab+b^2-4z^2\right)\)
\(=3\left[\left(a-b\right)^2-4z^2\right]\)
\(=3\left(a-b-2z\right)\left(a-b+2z\right)\)
a)\(81x^2-6yz-9y^2-z^2=\left(9x\right)^2-\left(9y^2+6yz+z^2\right)=\left(9x\right)^2-\left(3y+z\right)^2=\left(9x-3y-z\right)\left(9x+3y+z\right)\)b)\(x^2y-x^3-9y+9x=x^2\left(y-x\right)-9\left(y-x\right)=\left(x^2-9\right)\left(y-x\right)=\left(x-3\right)\left(x+3\right)\left(y-x\right)\)
c)\(3a^2-6ab+3b^2-12c^2=3\left(a^2-2ab+b^2-4c^2\right)=3\left[\left(a-b\right)^2-\left(2c\right)^2\right]=3\left(a-b-2c\right)\left(a-b+2c\right)\)
\(x^3-x^2-5x+125\)
\(=\left(x+5\right)\left(x^2-5x+25\right)-x\left(x+5\right)\)
\(=\left(x+5\right)\left(x^2-5x+25-x\right)\)
\(=\left(x+5\right)\left(x^2-6x+25\right)\)
\(x^6-x^4-9x^3+9x^2\)
\(=x^4\left(x^2-1\right)-9x^2\left(x-1\right)\)
\(=x^4\left(x-1\right)\left(x+1\right)-9x^2\left(x-1\right)\)
\(=x^2\left(x-1\right)\left[x^2\left(x+1\right)-9\right]\)
\(=x^2\left(x-1\right)\left(x^3+x^2-9\right)\)
\(x^4-4x^3+8x^2-16x+16\)
\(=\left(x^2+4\right)^2-4x\left(x^2+4\right)\)
\(=\left(x^2+4\right)\left(x^2+4-4x\right)\)
\(=\left(x^2+4\right)\left(x-2\right)^2\)
\(3a^2-6ab+3b^2-12c^2\)
\(=3\left(a^2-2ab+b^2-4c^2\right)\)
\(=3\left[\left(a-b\right)^2-\left(2c\right)^2\right]\)
\(=3\left(a-b+2c\right)\left(a-b-2c\right)\)
Phân tích đa thức thành nhân tử
a. 3ab ( x+ y) - 6ab ( y+ x)
=( x + y) ( 3ab - 6ab )
= ( x +y ) ( - 3ab)
b.7a (x - 3)+a2(x2 - 9)
=7a( x- 3) + a2 ( x2 - 32)
=7a ( x - 3 ) + a2 ( x- 3 ) ( x+3 )
= ( x- 3) . 7a + a2 ( x + 3)
= ( x- 3) ( 7a +a2x + 3a2)
c. 34 (x + y) -x -y
= 34 ( x+ y) - ( x+y)
=(x +y ) ( 34 - 1) = 33 ( x+ y)
d. 25 x4 - 942
=( 5x2 )2 - 942
=( 5x2 - 94 ) ( 5x2+94)
e.( 5a - b )2 - ( 2a +3b)2
=( 5a -b -2a - 3b) (5a -b + 2a + 3b)
=(3a - 4b) (7a+ 2b)
k. 22 -3a - b2 +3b
=( 22 - b2 ) + ( -3a +3b)
=( 2-b) (2+b) + 3( -a +b)
a) \(2x^2-2xy-5x+5y\)
\(=y\left(5-2x\right)-x\left(5-2x\right)\)
\(=\left(5-2x\right)\left(y-x\right).\)
b) \(8x^2+4xy-2ax-ay\)
\(=2x\left(4x-a\right)+y\left(4x-a\right)\)
\(=\left(2x+y\right)\left(4x-a\right)\)
c) \(x^3-4x^2+4x\)
\(=x\left(x^2-4x+4\right)\)
\(=x\left(x-2\right)^2\)
d) \(2xy-x^2-y^2+16\)
\(=-\left(x^2-2xy+y^2-4^2\right)\)
\(=-\left[\left(x-y\right)^2-4^2\right]\)
\(=-\left(x-y-4\right)\left(x-y+4\right)\)
e) \(x^2-y^2-2yz-z^2\)
\(=x^2-\left(y^2+2yz+z^2\right)\)
\(=x^2-\left(y+z\right)^2\)
\(=\left(x-y+z\right)\left(x+y+z\right)\)
g) \(3a^2-6ab+3b^2-12c^2\)
\(=3\left(a^2-2ab+b^2-4c^2\right)\)
\(=3\left[\left(a-b\right)^2-\left(2c\right)^2\right]\)
\(=3\left(a-b-2c\right)\left(a-b+2c\right)\)
a ) \(3a^2-6ab+3b^2-12c^2\)
\(=3\left(a^2-2ab+b^2-4c^2\right)\)
\(=3\left[\left(a-b\right)^2-\left(2c\right)^2\right]\)
\(=4\left(a-b-2c\right)\left(a-b+2c\right)\)
b ) \(x^2-25+y^2+2xy\)
\(=\left(x^2+2xy+y^2\right)-25\)
\(=\left(x+y\right)^2-5^2\)
\(=\left(x+y-5\right)\left(x+y+5\right)\)
c )
\(x^2y-x^3-9y+9x\)
\(=x^2\left(y-x\right)-9\left(y-x\right)\)
\(=\left(y-x\right)\left(x^2-9\right)\)
\(=\left(y-x\right)\left(x-3\right)\left(x+3\right)\)
d )\(x^2\left(x-1\right)+16\left(1-x\right)\)
\(=x^2\left(x-1\right)-16\left(x-1\right)\)
\(=\left(x-1\right)\left(x^2-16\right)\)
\(=\left(x-1\right)\left(x-4\right)\left(x+4\right)\)
Bài 1:
a) \(x^2-y^2-2yz-z^2\)
\(=x^2-\left(y^2+2yz+z^2\right)\)
\(=x^2-\left(y+z\right)^2\)
\(=\left(x+y+z\right)\left(x-y-z\right)\)
b) \(2xy-x^2-y^2+16\)
\(=16-\left(x^2-2xy+y^2\right)\)
\(=4^2-\left(x-y\right)^2\)
\(=\left(4+x-y\right)\left(4-x+y\right)\)
c) \(3a^2-6ab+3b^2-12c^2\)
\(=3\left(a^2-2ab+b^2-4c^2\right)\)
\(=3\left[\left(a^2-2ab+b^2\right)-\left(2c\right)^2\right]\)
\(=3\left[\left(a-b\right)^2-\left(2c\right)^2\right]\)
\(=3\left(a-b-2c\right)\left(a-b+2c\right)\)
Bài 2:
a) \(37,5\cdot8,5-7,5\cdot3,4+6,6\cdot7,5+1,5\cdot37,5\)
\(=\left(37,5\cdot8,5+1,5\cdot37,5\right)-\left(7,5\cdot3,4-6,6\cdot7,5\right)\)
\(=37,5\cdot\left(8,5+1,5\right)-7,5\cdot\left(3,4-6,6\right)\)
\(=37,5\cdot10-7,5\cdot10\) (mk đoán đề bạn chép sai)
\(=10\cdot\left(37,5-7,5\right)\)
\(=10\cdot30\)
\(=300\)
b) \(35^2+40^2-25^2+80\cdot35\)
\(=\left(40^2+2\cdot40\cdot35+35^2\right)-25^2\)
\(=\left(40+35\right)^2-25^2\)
\(=75^2-25^2\)
\(=\left(75+25\right)\left(75-25\right)\)
\(=100\cdot50\)
\(=5000\)
Bài 1:
a, \(x^2-y^2-2yz-z^2=x^2-\left(y^2+2yz+z^2\right)\)
\(=x^2-\left(y+z\right)^2=\left(x-y-z\right)\left(x+y+z\right)\)
b, \(2xy-x^2-y^2+16=16-\left(x^2-2xy+y^2\right)\)
\(=16-\left(x-y\right)^2=\left(4-x+y\right)\left(4+x-y\right)\)
c, \(3a^2-6ab+3b^2-12c^2\)
\(=3\left(a-b\right)^2-12c^2=3\left[\left(a-b\right)^2-4c^2\right]\)
\(=3\left(a-b+2c\right)\left(a-b-2c\right)\)
Bài 2:
a, \(37,5.8,5-7,5.3,4+6,6.7,5+1,5.37,5\)
\(=37,5.\left(8,5+1,5\right)-7,5.\left(3,4+6,6\right)\)
\(=37,5.10-7,5.10=10.\left(37,5-7,5\right)\)
\(=10.30=300\)
b, \(35^2+40^2-25^2+80.35\)
\(=\left(40^2+2.40.35+35^2\right)-25^2\)
\(=\left(40+35\right)^2-25^2=75^2-25^2\)
\(=\left(75-25\right)\left(75+25\right)=50.100=5000\)
a: \(=\left(m^2-2m+1\right)-\left(n^2-2np+p^2\right)\)
\(=\left(m-1\right)^2-\left(n-p\right)^2\)
\(=\left(m-1-n+p\right)\left(m-1+n-p\right)\)
b: \(=3\left(a^2-2ab+b^2-4c^2\right)\)
\(=3\left[\left(a-b\right)^2-\left(2c\right)^2\right]\)
\(=3\left(a-b-2c\right)\left(a-b+2c\right)\)