a: \(\dfrac{x^3-x}{3x+3}=\dfrac{x\left(x-1\right)\left(x+1\right)}{3\left(x+1\right)}=\dfrac{x\left(x-1\right)}{3}\)

b: \(\dfrac{x^2-4xy+4y^2-4}{2x^2-4xy+4x}\)

\(=\dfrac{\left(x-2y\right)^2-4}{2x\left(x-2y+2\right)}\)

\(=\dfrac{x-2y-2}{2x}\)

\(A=\dfrac{2x^2\left(3x-4y+2\right)}{x\left(3x+y\right)\left(3x-y\right)}=\dfrac{2x\left(3x-4y+2\right)}{\left(3x+y\right)\left(3x-y\right)}\\ A=\dfrac{2\left(3-8+2\right)}{\left(3+2\right)\left(3-2\right)}=\dfrac{2\left(-3\right)}{5}=\dfrac{-6}{5}\)

bài 1 : a. x^3 +27 -54-x^3 =-27

b. 8x^3 +y^3 -8x^3 +y^3 =2y^3

c. (2x-1+2x+2)(2x-1-2x-2)=(4x+1).(-3)=-12x-3

d. a^3 +b^3 +3ab(a+b) -3ab(a+b)=a^3+b^3

 a. (x-1)^2 =5^2

x-1=5

x=6

A=(4x^2 +4x+1 )+1 

A=(2x+1)^2 +1 >0

B=(x^2 -2x+1 )+x^2

B=(x-1)^2 +x^2 >0

\(\left(3x-2y\right)^3+\left(y+2x\right)^3-\left(4x-5y\right)\left(16x^2+20xy+25y^2\right)\)

\(=27x^3-54x^2y+36xy^2-8y^3+y^3+6xy^2+12x^2y+8x^3-\left(64x^3-125y^3\right)\)

\(=35x^3-42x^2y+42xy^2-7y^3-64x^3+125y^3\)

\(=-29x^3-42x^2y+42xy^2+118y^3\)

Thiếu đề

A=−√32

A=−0.86602540…

\(D=\frac{3\sqrt{1-4x+4x^2}}{2x-1}=\frac{3\sqrt{\left(2x\right)^2-2.2x.1+1^2}}{2x-1}=\frac{3\sqrt{\left(2x-1\right)^2}}{2x-1}=\frac{3.\left(2x-1\right)}{2x-1}=3\)

mình làm lại nè, bài kia mình hơi nhầm 1 chút

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

p/s tới 1 người

hôm nay onl nhưng ko chat đc,,,pp nha nn