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28 tháng 9 2019

ko ai thèm trả lời đâu cu

28 tháng 9 2019

a) \(4x^2-6x=2x\left(2x-3\right)\)

b) \(9x^4y^3+3x^2y^4=3x^2y^3\left(3x^2+y\right)\)

c) \(3\left(x-y\right)-5x\left(y-x\right)=3\left(x-y\right)+5x\left(x-y\right)\)

\(=\left(5x+3\right)\left(x-y\right)\)

d) \(x^3-2x^2+5x=x\left(x^2-2x+5\right)\)

e) \(5\left(x+3y\right)-15x\left(x+3y\right)=\left(5-15x\right)\left(x+3y\right)\)

\(=5\left(1-3x\right)\left(x+3y\right)\)

f) \(2x^2\left(x+1\right)-4\left(x+1\right)=\left(2x^2-4\right)\left(x+1\right)\)

\(=\left(\sqrt{2}x-2\right)\left(\sqrt{2}x+2\right)\left(x+1\right)\)

29 tháng 9 2019

a. \(8x\left(x-2017\right)-2x+4034=0\)

\(8x\left(x-2017\right)-2\left(x-2017\right)=0\)

\(\left(8x-2\right)\left(x-2017\right)=0\)

\(\Rightarrow TH1:8x-2=0\)

\(8x=2\)

\(x=\frac{1}{4}\)

\(TH2:x-2017=0\)

\(x=2017\)

Vậy \(x\in\left\{\frac{1}{4};2017\right\}\)

29 tháng 9 2019

Bài 1 

a) \(8x\left(x-2017\right)-2x+4034=0\)

\(\Rightarrow8x\left(x-2017\right)-2\left(x-2017\right)=0\)

\(\Rightarrow\left(x-2017\right)\left(4x-1\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x=2017\\x=\frac{1}{4}\end{cases}}\)

6 tháng 11 2019

\(C1:=3+1-3y\)

\(=4-3y\)

\(C2:\)

\(a.=3x\left(2y-1\right)\)

\(b.=\left(x-y\right)\left(x+y\right)+4\left(x+y\right)\)

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

\(C3:\)

\(a.6x^2+2x+12x-6x^2=7\)

\(14x=7\)

\(x=\frac{1}{2}\)

\(b.\frac{1}{5}x-2x^2+2x^2+5x=-\frac{13}{2}\)

\(\frac{26}{5}x=-\frac{13}{2}\)

\(x=-\frac{13}{2}\times\frac{5}{26}\)

\(x=-\frac{5}{4}\)

3 tháng 7 2020

Bạn Moon làm kiểu gì vậy ?

1) \(\left(3x^2y^2+x^2y^2\right):\left(x^2y^2\right)-3y\)

\(=\left[\left(x^2y^2\right)\left(3+1\right)\right]:\left(x^2y^2\right)-3y\)

\(=4-3y\)

2) a, \(6xy-3x=\left(3x\right)\left(2y-1\right)\)

b, \(x^2-y^2+4x+4y=\left(x+y\right)\left(x-y\right)+4\left(x+y\right)\)

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

3) a,  \(2x\left(3x+1\right)+\left(4-2x\right)3x=7\)

\(< =>6x^2+2x+12x-6x^2=7\)

\(< =>14x=7< =>x=\frac{7}{14}\)

b, \(\frac{1}{2}x\left(\frac{2}{5}-4x\right)+\left(2x+5\right)x=-6\frac{1}{2}\)

\(< =>\frac{x}{2}.\frac{2}{5}-\frac{x}{2}.4x+2x^2+5x=-\frac{13}{2}\)

\(< =>\frac{x}{5}-2x^2+2x^2+5x=-\frac{13}{2}\)

\(< =>\frac{26x}{5}=\frac{-13}{2}\)

\(< =>26x.2=\left(-13\right).5\)

\(< =>52x=-65< =>x=-\frac{65}{52}=-\frac{5}{4}\)

làm nhiều rồi 

hehe

hihi

30 tháng 8 2019

3/

a/ \(A=\left(x-y\right)^2+\left(x+y\right)^2.\)

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

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

\(A=2x^2+2y^2\)

b/ \(B=\left(2a+b\right)^2-\left(2a-b\right)^2\)

\(B=\left(4a^2+4ab+b^2\right)-\left(4a^2-4ab+b^2\right)\)

\(B=4a^2+4ab+b^2-4a^2+4ab-b^2\)

\(B=8ab\)

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

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

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

\(C=4xy\)

d/ \(D=\left(2x-1\right)^2-2\left(2x-3\right)^2+4\)

\(D=\left(4x^2-4x+1\right)-2\left(4x^2-12x+9\right)+4\)

\(D=4x^2-4x+1-8x^2+24x-18+4\)

\(D=-4x^2+20x-13\)

1 tháng 12 2019

a) \(=\frac{2\left(x+y\right)+5\left(x+y\right)}{2\left(x+y\right)-5\left(x+y\right)}\)

\(=\frac{7\left(x+y\right)}{-3\left(x+y\right)}=\frac{-7}{3}\)

b)\(=\frac{3x\left(x+y\right)}{y}\)

c) \(\frac{5\left(x-y\right)+3\left(x-y\right)}{10\left(x-y\right)}\)

\(=\frac{8\left(x-y\right)}{10\left(x-y\right)}=\frac{4}{5}\)

1 tháng 12 2019

a) \(\frac{2x+2y+5x+5y}{2x+2y-5x-5y}=\frac{7x+7y}{-3x-3y}=\frac{7\left(x+y\right)}{-3\left(x+y\right)}=-\frac{7}{3}.\)

b) \(\frac{15x\left(x+y\right)^3}{5y\left(x+y\right)^2}=\frac{3x\left(x+y\right)}{y}=\frac{3x^2+3xy}{y}\)

c) \(\frac{5\left(x-y\right)-3\left(y-x\right)}{10\left(x-y\right)}=\frac{5\left(x-y\right)+3\left(x-y\right)}{10\left(x-y\right)}=\frac{8\left(x-y\right)}{10\left(x-y\right)}=\frac{4}{5}\)

d) \(\frac{3\left(x-y\right)\left(x-z\right)^2}{6\left(x-y\right)\left(x-z\right)}=\frac{x-z}{2}\)

h) \(\frac{3x\left(1-x\right)}{2\left(x-1\right)}=-\frac{3x\left(x-1\right)}{2\left(x-1\right)}=\frac{-3x}{2}\)

j) \(\frac{6x^2y^2}{8xy^5}=\frac{3x}{4y^3}\)

Câu b) bạn xem lại nhé.

Học tốt ^3^

đợi mink tí

30 tháng 8 2019

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

\(b,\left(x-1\right)^2=x^2-2x+1\)

\(c,\left(x^2+y^2\right)^2=x^4+2x^2y^2+y^4\)

\(d,\left(x^3+2y^2\right)^2=x^6+4x^3y^2+4y^4\)

29 tháng 6 2018

BÀI 1:

a) \(x^4+2x^2y+y^2=\left(x^2+y\right)^2\)

b) \(\left(2a+b\right)^2-\left(2b+a\right)^2=\left(2a+b+2b+a\right)\left(2a+b-2b-a\right)\)

\(=\left(3a+3b\right)\left(a-b\right)=3\left(a+b\right)\left(a-b\right)\)

c) \(\left(a^3-b^3\right)+\left(a-b\right)^2=\left(a-b\right)\left(a^2+ab+b^2\right)+\left(a-b\right)^2\)

\(=\left(a-b\right)\left[a^2+ab+b^2+\left(a-b\right)\right]=\left(a-b\right)\left(a^2+ab+b^2+a-b\right)\)

d) \(\left(x^2+1\right)^2-4x^2=\left(x^2+1-2x\right)\left(x^2+1+2x\right)=\left(x-1\right)^2\left(x+1\right)^2\)

e) \(\left(y^3+8\right)+\left(y^2-4\right)=\left(y+2\right)\left(y^2-y+2\right)\)

f) \(1-\left(x^2-2xy+y^2\right)=1-\left(x-y\right)^2=\left(1-x+y\right)\left(1+x-y\right)\)

g) \(x^4-1=\left(x-1\right)\left(x+1\right)\left(x^2+1\right)\)

h) ktra lại đề

m) \(\left(x-a\right)^4-\left(x+a\right)^4=-8ax\left(a^2+x^2\right)\)

29 tháng 6 2018

a ) x^4 + 2x^2y + y^2 

   Dùng hằng đẳng thức ( a + b )^2 = a^2 +2ab + b^2

   = ( x^2 + y )^2

b ) ( 2a + b )^2 - ( 2b + a )^2

   = ( 4a^2 + 4ab + b^2 ) - ( 4b^2 + 4ab + a^2 )

   = 4a^2 + 4ab + b^2 - 4b^2 - 4ab - a^2

   = 3a^2- 3b^2

   = 3( a^2 - b^2 ) 

24 tháng 9 2019

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

\(=x^2y^2\left(y-x\right)-y^2z^2\left[\left(y-x\right)-\left(z-x\right)\right]-z^2x^2\left(z-x\right)\)

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

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

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

Xet \(xy^2+y^2z-z^2y-z^2x=x\left(y-z\right)\left(y+z\right)+yz\left(y-z\right)=\left(y-z\right)\left(xy+yz+zx\right)\)

Vay \(x^2y^2\left(y-x\right)+y^2z^2\left(z-y\right)-z^2x^2\left(z-x\right)=\left(y-x\right)\left(x-z\right)\left(y-z\right)\left(xy+yz+zx\right)\)

24 tháng 9 2019

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

\(=x^2y^3-x^3y^2+y^2z^3-y^3z^2-z^3x^2+z^2x^3\)

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

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

\(=\left(x-z\right)\left(xy^3+y^3z-y^2x^2-y^2xz-y^2z^2+z^2x^2\right)\)

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