Question

tìm x,y biết:

a,(x+y)²+(1+x)(1+y)=0

b,(3x-2)(x+1)²(3x+8)=-16

c,(4x-5)(2x-3)(x-1)=9

d,(2x²+x-2013)²+4(x²-5x-2012)²=4(2x²+x-2013)(x²-5x-2012)

Answer 1

I don't now 

sorry 

...................

nha

Answer 2

b)  \(\left(3x-2\right)\left(x+1\right)^2\left(3x+8\right)=-16\)

\(\Leftrightarrow\)\(\left(3x-2\right)\left(3x+3\right)^2\left(3x+8\right)+144=0\)

Đặt:  \(3x+3=a\)pt trở thành:

\(\left(a-5\right)a^2\left(a+5\right)+144=0\)

\(\Leftrightarrow\)\(a^4-25a^2+144=0\)

\(\Leftrightarrow\)\(\left(a-4\right)\left(a-3\right)\left(a+3\right)\left(a+4\right)=0\)

đến đây bạn tìm a rồi tính x

c)  \(\left(4x-5\right)\left(2x-3\right)\left(x-1\right)=9\)

\(\Leftrightarrow\)\(\left(4x-5\right)\left(4x-6\right)\left(4x-4\right)-72=0\)

Đặt   \(4x-5=a\)pt trở thành:

\(a\left(a-1\right)\left(a+1\right)-72=0\)

\(\Leftrightarrow\)\(a^3-a-72=0\)

p/s: ktra lại đề

d)  \(\left(2x^2+x-2013\right)^2+4\left(x^2-5x-2012\right)^2=4\left(2x^2+x-2013\right)\left(x^2-5x-2012\right)\)

\(\Leftrightarrow\)\(\left(2x^2+x-2013\right)^2+4\left(x^2-5x-2012\right)^2-4\left(2x^2+x-2013\right)\left(x^2-5x-2012\right)=0\)

\(\Leftrightarrow\)\(\left[\left(2x^2+x-2013\right)-2\left(x^2-5x-2012\right)\right]^2=0\)

\(\Leftrightarrow\)\(\left(11x+2011\right)^2=0\)

đến đây làm nốt