K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

\(=\left(4x-2y\right)\left(4x+2y\right)+\left(x-5y\right)^2-\left(9x^2+12xy+4y^2\right)-7x^2+21xy\)

\(=16x^2-4y^2-7x^2+21xy-9x^2-12xy-4y^2+\left(x-5y\right)^2\)

\(=-8y^2+9xy+x^2-10xy+25y^2\)

\(=x^2-xy+17y^2\)

2 tháng 10 2021

2a) pt <=> (x + 6)^2 = 0

<=> x = -6

b) pt <=> (4x - 1)^2 = 0

<=> x = 1/4

c) pt<=> (x + 1)^3 = 0

<=> x = -1

Bài 1:

a: Ta có: \(A=\left(4x+3y\right)^2+\left(4x-3y\right)^2\)

\(=16x^2+24xy+9y^2+16x^2-24xy+9y^2\)

\(=32x^2+18y^2\)

b: Ta có: \(B=\left(x-2\right)^3-\left(x+2\right)^3\)

\(=x^3-6x^2+12x-8-x^3-6x^2-12x-8\)

\(=-12x^2-24\)

Bài 2: 

a: Ta có: \(x^2+12x+36=0\)

\(\Leftrightarrow x+6=0\)

hay x=-6

b: Ta có: \(16x^2-8x+1=0\)

\(\Leftrightarrow4x-1=0\)

hay \(x=\dfrac{1}{4}\)

Bài 1: 

a: Ta có: \(A=\left(4x+3y\right)^2+\left(4x-3y\right)^2\)

\(=16x^2+24xy+9y^2+16x^2-24xy+9y^2\)

\(=32x^2+18y^2\)

b: Ta có: \(B=\left(x-2\right)^3-\left(x+2\right)^3\)

\(=x^3-6x^2+12x-8-x^3-6x^2-12x-8\)

\(=-12x^2-24\)

c: Ta có: \(C=\left(x+2y\right)^2+2\left(x+2y\right)\left(x-2y\right)+\left(x-2y\right)^2\)

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

\(=4x^2\)

14 tháng 12 2022

`a)7x^3y^2+14x^2y^3+7xy^4`

`=7xy^2(x^2+2xy+y^2)`

`=7xy^2(x+y)^2`

______________________________________________

`b)x^2-xy+5x-5y`

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

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

______________________________________________

`c)3x^2-6xy-12+3y^2`

`=3(x^2-2xy-4+y^2)`

`=3[(x-y)^2-4]`

`=3(x-y-2)(x-y+2)`

a)7x3y2+14x2y3+7xy4

=7xy2(x2+2xy+y2)

=7xy2(x+y)2

b)x2-xy + 5x - 5y

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

=(x-y) (x+5)

 

a: (3x^2-4)(x+3y)

=3x^2*x+3x^2*3y-4x-4*3y

=3x^3+9x^2y-4x-12y

b: (c+3)(x^2+3x)

=c*x^2+c*3x+3x^2+9x

=cx^2+3cx+3x^2+9x

c: (xy-1)(xy+5)

=xy*xy+5xy-xy-5

=x^2y^2+4xy-5

d: (3x+5y)(2x-7y)

=3x*2x-3x*7y+5y*2x-5y*7y

=6x^2-21xy+10xy-35y^2

=6x^2-11xy-35y^2

e: -(x-1)(-x^2+2y)

=(x-1)(x^2-2y)

=x^3-2xy-x^2+2y

f: (-x^2+2y)(x^2+2y)

=(2y)^2-x^4

=4y^2-x^4

21 tháng 8 2023

Bài 12:

a) \(\left(\dfrac{1}{2}x+4\right)^2\)

\(=\left(\dfrac{1}{2}x\right)^2+2\cdot\dfrac{1}{2}x\cdot4+4^2\)

\(=\dfrac{1}{4}x^2+4x+16\)

b) \(\left(7x-5y\right)^2\)

\(=\left(7x\right)^2-2\cdot7x\cdot5y+\left(5y\right)^2\)

\(=49x^2-70xy+25y^2\)

c) \(\left(6x^2+y^2\right)\left(y^2-6x^2\right)\)

\(=\left(y^2+6x^2\right)\left(y^2-6x^2\right)\)

\(=y^4-36x^4\)

d) \(\left(x+2y\right)^2\)

\(=x^2+2\cdot x\cdot2y+\left(2y\right)^2\)

\(=x^2+4xy+4y^2\)

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

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

\(=x^2-9y^2\)

f) \(\left(5-x\right)^2\)

\(=5^2-2\cdot5\cdot x+x^2\)

\(=25-10x+x^2\)

21 tháng 8 2023

\(11,\)

\(a,\left(7x+4\right)^2-\left(7x+4\right)\left(7x-4\right)\)

\(=\left(7x+4\right)\left(7x+4-7x+4\right)\)

\(=\left(7x+4\right).8=56x+32\)

\(b,\left(x+2y\right)^2-6xy\left(x+2y\right)\)

\(=\left(x+2y\right)\left(x+2y-6xy\right)\)

8 tháng 9 2021

\(a,-2xy^2\left(x^3y-2x^2y^2+5xy^3\right)\\ =-2x^4y^3+4x^3y^4-10x^2y^5\\ b,\left(-2x\right)\left(x^3-3x^2-x+1\right)\\ =-2x^4+6x^3+2x^2-2x\\ c,\left(-10x^3+\dfrac{2}{5}y-\dfrac{1}{3}z\right)\left(-\dfrac{1}{2}zy\right)\\ =5x^3yz-\dfrac{1}{5}y^2z+\dfrac{1}{6}yz^2\\ d,3x^2\left(2x^3-x+5\right)=6x^5-3x^3+15x^2\\ e,\left(4xy+3y-5x\right)x^2y=4x^3y^2+3x^2y^2-5x^3y\\ f,\left(3x^2y-6xy+9x\right)\left(-\dfrac{4}{3}xy\right)\\ =-4x^3y^2+8x^2y^2-12x^2y\)

17 tháng 7 2018

\(\left(-4x+2y\right)\left(-4x-2y\right)+\left(x-5y\right)^2-\left(3x+2y\right)^2-7x\left(x-3y\right)\)

\(=\left(16x^2-4y^2\right)+\left(x^2-10xy+25y^2\right)-\left(9x^2+12xy+4y^2\right)-7x^2+21xy\)

\(=16x^2-4y^2+x^2-10xy+25y^2-9x^2-12xy-4y^2-7x^2+21xy\)

\(=x^2+17y^2-xy\)

\(=\left(4x-2y\right)\left(4x+2y\right)+x^2-10xy+25y^2-9x^2-12xy-4y^2-7x^2+21xy\)

\(=16x^2-4y^2-15x^2-xy+21y^2\)

\(=x^2-xy+17y^2\)

a: =>A-B=3x^2y-4xy^2+x^2y-2xy^2=4x^2y-6xy^2

b: =>B-A=-7xy^2+8x^2y-5xy^2+6x^2y=-12xy^2+14x^2y

=>A-B=12xy^2-14x^2y

c: =>B-A=8x^2y^3-4x^3y-3x^2y^3+5x^3y^2=5x^2y^3+x^3y^2

=>A-B=-5x^2y^3-x^3y^2

d: =>A-B=2x^2y^3-7x^3y+6x^2y^3+3x^3y^2=8x^2y^3-7x^3y+3x^3y^2