K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Các câu hỏi dưới đây có thể giống với câu hỏi trên
2T
17 tháng 8 2019
\(4x^4-9x^2\)
\(=\left(2x^2\right)^2-\left(3x\right)^2\)
\(=\left(2x^2-3x\right)\left(2x^2+3x\right)\)
15 tháng 7 2016
a) \(xy+3x-7y-21\)
\(\Leftrightarrow\left(xy+3x\right)-\left(7y+21\right)\)
\(\Leftrightarrow x\left(y+3\right)-7\left(y+3\right)\)
\(\Leftrightarrow\left(x-7\right)\left(y+3\right)\)
15 tháng 7 2016
b) \(2xy-15-6x+5y\)
\(\Leftrightarrow\left(2xy-6x\right)-\left(15-5y\right)\)
\(\Leftrightarrow x\left(2y-6\right)-5\left(3-y\right)\)
\(\Leftrightarrow2x\left(y-3\right)+5\left(y-3\right)\)
\(\Leftrightarrow\left(2x+5\right)\left(y-3\right)\)
KV
20 tháng 10 2023
a) Xem lại đề
b) x³ - 4x²y + 4xy² - 9x
= x(x² - 4xy + 4y² - 9)
= x[(x² - 4xy + 4y² - 3²]
= x[(x - 2y)² - 3²]
= x(x - 2y - 3)(x - 2y + 3)
c) x³ - y³ + x - y
= (x³ - y³) + (x - y)
= (x - y)(x² + xy + y²) + (x - y)
= (x - y)(x² + xy + y² + 1)
d) 4x² - 4xy + 2x - y + y²
= (4x² - 4xy + y²) + (2x - y)
= (2x - y)² + (2x - y)
= (2x - y)(2x - y + 1)
e) 9x² - 3x + 2y - 4y²
= (9x² - 4y²) - (3x - 2y)
= (3x - 2y)(3x + 2y) - (3x - 2y)
= (3x - 2y)(3x + 2y - 1)
f) 3x² - 6xy + 3y² - 5x + 5y
= (3x² - 6xy + 3y²) - (5x - 5y)
= 3(x² - 2xy + y²) - 5(x - y)
= 3(x - y)² - 5(x - y)
= (x - y)[(3(x - y) - 5]
= (x - y)(3x - 3y - 5)
AM
19 tháng 6 2015
b)x2+2xy+y2-16=(x+y)2-42=(x+y+4)(x+y-4)
c)3x2+5x-3xy-5y=x(3x+5)-y(3x+5)=(3x+5)(x-y)
d)4x2-6x3y-2x2+8x=2x(2x-3x2y-x+4)
e)x2-4-2xy+y2=(x2-2xy+y2)-4=(x-y)2-22=(x-y-2)(x-y+2)
k)x2-y2-z2-2yz=x2-(y+z)2=(x-y-z)(x+y+z)
m)6xy+5x-5y-3x2-3y2=3(x2-2xy+y2)+5(x-y)=3(x-y)2+5(x-y)=(x-y)(3x-3y+5)
TV
26 tháng 2 2020
\(\text{a) 7-2x=22-9x}\)
\(\Leftrightarrow\text{7-2x-22+9x=0}\)
\(\Leftrightarrow-15+7x=0\)
\(\Leftrightarrow7x=15\)
\(\Leftrightarrow x=\frac{15}{7}\)
Học tốt
#Thảo Vy#
GH
27 tháng 7 2023
a
\(xy+3x-7y-21\\ =\left(xy+3x\right)-\left(7y+21\right)\\ =x\left(y+3\right)-7\left(y+3\right)\\ =\left(y+3\right)\left(x-7\right)\)
b
\(2xy-15-6x+5y\\ =\left(2xy-6x\right)-\left(15-5y\right)\\ =2x\left(y-3\right)-5\left(3-y\right)\\ =2x\left(y-3\right)+5\left(y-3\right)\\ =\left(y-3\right)\left(2x+5\right)\)
c Đề phải là \(\left(2x^2y+2xy^2-x-y\right)\) mới phân tích được: )
\(=2xy\left(x+y\right)-\left(x+y\right)\\ =\left(x+y\right)\left(2xy-1\right)\)
d
\(7x^3y-3xyz-21x^2+9z\\ =\left(7x^3y-21x^2\right)-\left(3xyz-9z\right)\\ =7x^2\left(xy-3\right)-3z\left(xy-3\right)\\ =\left(xy-3\right)\left(7x^2-3z\right)\)
e
\(4x^2-2x-y^2-y\\ =\left(2x\right)^2-y^2-\left(2x+y\right)\\ =\left(2x-y\right)\left(2x+y\right)-\left(2x+y\right)\\ =\left(2x+y\right)\left(2x-y-1\right)\)
f
\(9x^2-25y^2-6x+10y\\ =\left(3x\right)^2-\left(5y\right)^2-\left(6x-10y\right)\\ =\left(3x-5y\right)\left(3x+5y\right)-2\left(3x-5y\right)\\ =\left(3x-5y\right)\left(3x+5y-2\right)\)
27 tháng 7 2023
a: =x(y+3)-7(y+3)
=(y+3)(x-7)
b: \(=2xy-6x+5y-15\)
=2x(y-3)+5(y-3)
=(y-3)(2x+5)
c: \(=2xy\left(x+y\right)-\left(x+y\right)=\left(x+y\right)\left(2xy-1\right)\)
d: \(=xy\left(7x^2-3z\right)-3\left(7x^2-3z\right)\)
=(7x^2-3z)(xy-3)
e: =4x^2-y^2-2x-y
=(2x-y)(2x+y)-(2x+y)
=(2x+y)(2x-y-1)
f: =(3x-5y)(3x+5y)-2(3x-5y)
=(3x-5y)(3x+5y-2)
25 tháng 8 2018
a^2-25-2ab+b^2
= (a^2 - 2ab + b^2 ) - 5^2
= (a -b)^2 - 5^2 = ( a - b - 5 ) ( a - b + 5 )
5x^2-6xy+y^2
= (3x)^2 - 2.3x.y + y^2 - (2x)^2
= (3x - y)^2 - (2x)^2
= ( 3x - y - 2x ) ( 3x - y + 2x ) = ( x - y) ( 5x - y )
2x^3-8x^2+8x
= 2x^3 - 4x^2 - 4x^2 + 8x
= 2x^2(x - 2) - 4x(x-2)
= (2x^2 - 4x)(x-2)
= 2x(x-2)(x-2) = 2x .(x-2)^2
5x-5y-3x^2+6xy-3y^2
=5(x - y) - 3(x^2 - 2xy + y^2 )
= 5(x-y) - 3(x-y)^2 = (x-y)[ 5 - 3(x-y) ]
4x^4-9x^2
= (2x^2)^2 - (3x)^2
= (2x^2 - 3x)(2x^2 + 3x)
= x(2x - 3)x(2x + 3 ) = x^2(2x - 3)(2x + 3 )
Y
25 tháng 8 2018
a) \(a^2-25-2ab+b^2\)
\(=\left(a-b\right)^2-25\)
\(=\left(a-b-5\right)\left(a-b+5\right)\)
b) \(5x^2-6xy+y^2\)
\(=\left(3x\right)^2-2.3x.y+y^2-\left(2x\right)^2\)
\(=\left(3x-y\right)^2-\left(2x\right)^2\)
\(=\left(3x-y-2x\right)\left(3x-y+2x\right)\)
\(=\left(x-y\right)\left(5x-y\right)\)
c) \(2x^3-8x^2+8x\)
\(=2x^3-4x^2-4x^2+8x\)
\(=2x^2\left(x-2\right)-4x\left(x-2\right)\)
\(=2x\left(x-2\right)\left(x-2\right)\)
\(=2x\left(x-2\right)^2\)
d) \(5x-5y-3x^2+6xy-3y^2\)
\(=5\left(x-y\right)-3\left(x^2-2xy+y^2\right)\)
\(=5\left(x-y\right)-3\left(x-y\right)^2\)
\(=\left(x-y\right)\left[5-3\left(x-y\right)\right]\)
e) \(4x^4-9x^2\)
\(=\left(2x^2\right)^2-\left(3x\right)^2\)
\(=\left(2x^2-3x\right)\left(2x^2+3x\right)\)
\(=x\left(2x-3\right).x\left(2x+3\right)\)
\(=x^2\left(2x-3\right)\left(2x+3\right)\)
f) \(x^8+4\)
\(=\left(x^4\right)^2+2.x^4.2+2^2-2.x^4.2\)
\(=\left(x^4+2\right)^2-4x^4\)
\(=\left(x^4+2\right)^2-\left(2x^2\right)^2\)
\(=\left(x^4+2-2x^2\right)\left(x^4+2+2x^2\right)\)
i) \(4x^2-y^2+4x+1\)
\(=\left(2x\right)^2+2.2x+1-y^2\)
\(=\left(2x+1\right)^2-y^2\)
\(=\left(2x+1-y\right)\left(2x+1+y\right)\)
j) \(3x^2-7x+10\)
\(=3\left(x^2-\dfrac{7}{3}x+\dfrac{10}{3}\right)\)
\(=3\left(x^2-2.x.\dfrac{7}{6}+\dfrac{49}{36}-\dfrac{49}{36}+\dfrac{10}{3}\right)\)
\(=3\left[\left(x-\dfrac{7}{6}\right)^2+\dfrac{71}{36}\right]\)
g) \(x^5+x+1\)
\(=x^5+x^4+x^3-x^4-x^3-x^2+x^2+x+1\)
\(=\left(x^5+x^4+x^3\right)-\left(x^4+x^3+x^2\right)+\left(x^2+x+1\right)\)
\(=x^3\left(x^2+x+1\right)-x^2\left(x^2+x+1\right)+\left(x^2+x+1\right)\)
\(=\left(x^2+x+1\right)\left(x^3-x^2-1\right)\)
h) \(x^4+2019x^2+2018x+2019\)
\(=\left(x^4-x\right)+\left(2019x^2+2019x+2019\right)\)
\(=x\left(x^3-1\right)+2019\left(x^2+x+1\right)\)
\(=x\left(x-1\right)\left(x^2+x+1\right)+2019\left(x^2+x+1\right)\)
\(=\left(x^2+x+1\right)\left[x\left(x-1\right)+2019\right]\)
\(=\left(x^2+x+1\right)\left(x^2-x+2019\right)\)
(9x-5y)(2x+7y)-(4x+3y)(8x-y)
=18x2+63xy-10xy-35y2-32x2+4xy-24xy+3y2
=-14x2-33xy-32y2