ĐKXĐ: \(x\ge\sqrt[3]{7}\)

\(4x^3-x^2+2x-32+\left(x^3-4\right)\left(\sqrt{x^3-7}-1\right)=0\)

\(\Leftrightarrow\left(x-2\right)\left(4x^2+7x+16\right)+\dfrac{\left(x^3-4\right)\left(x-2\right)\left(x^2+2x+4\right)}{\sqrt{x^3-7}+1}=0\)

\(\Leftrightarrow\left(x-2\right)\left(4x^2+7x+16+\dfrac{\left(x^3-4\right)\left(x^2+2x+4\right)}{\sqrt{x^3-7}+1}\right)=0\)

\(\Leftrightarrow x=2\) (ngoặc đằng sau luôn dương do \(x^3-4=x^3-7+3>0\))

2.

\(\Leftrightarrow\left(2x^3\right)^3+2x^3=x^3+3x^2+3x+1+x+1\)

\(\Leftrightarrow\left(2x^3\right)^3+2x^3=\left(x+1\right)^3+x+1\)

Đặt \(\left\{{}\begin{matrix}2x^3=a\\x+1=b\end{matrix}\right.\)

\(\Rightarrow a^3-b^3+a-b=0\Leftrightarrow\left(a-b\right)\left(a^2+ab+b^2+1\right)=0\)

\(\Leftrightarrow a=b\)

\(\Rightarrow2x^3=x+1\Leftrightarrow\left(x-1\right)\left(2x^2+2x+1\right)=0\)

\(5^2+\left(28-3x\right)=5^3\)

\(25+\left(28-3x\right)=125\)

\(\left(28-3x\right)=125-25\)

\(\left(28-3x\right)=100\)

\(3x=28-100\)

\(3x=-72\)

\(x=-72:3\)

\(x=-24\)

5²+(28-3x)=5³

<=>25+(28-3x)=125

=>28-3x=125-25

=>28-3x=100

=>3x=100-28

=>3x=72

=>x=72:3

=>x=24

5² + (28 - 3x) = 5³ 

28 - 3x = 5³ - 5²

28 - 3x = 100

3x = 28 - 100

3x = -72

x = 72 : 3

x = -24

#)Giải :

a) \(M=\left(3x^3+3x^2y-3xy^2+xy\right)-\left(2x^3-3x^2y-3xy^2+xy+1\right)\)

\(M=\left(3x^3-2x^3\right)+\left(3x^2y-3x^2y\right)+\left(-3xy^2+3xy^2\right)-\left(xy-xy\right)+1\)

\(M=x^3+1\)

b) \(M=-28\Leftrightarrow1+x^3=-28\)

\(\Rightarrow x^3=-27=\left(-3\right)^3=-3\)

Vậy ..................................................

trả lời 

B=-3

chúc bn 

hc tốt

\(a,=27-5\sqrt{3x}\\ b,=3\sqrt{2x}-10\sqrt{2x}+21\sqrt{2x}+28=14\sqrt{2x}+28\)

b ) -2(3x+2)-3 =28

-6x-4-3=28

-6x = 28 +4+3

-6x = 35

x =\(\dfrac{35}{-6}\)= \(\dfrac{-35}{6}\)= -5,8

vậy x= -5,8

c ) -(x+3)-5(x-7)=10x-20

-(x+3)-5x+35=10x-20

-x+3-5x+35=10x-20

-x-5x-10x=-20-3-35

-16x=-58

x=\(\dfrac{-58}{-16}\)=\(\dfrac{58}{16}\)=3,625

vậy x =3,625

d)2x+37=-6(3x-8)

2x+37=-18x+48

2x+18x=48-37

20x=11

x=\(\dfrac{11}{20}\)=0,55

vậy x=0,55

a) Ta có: \(4\left(x-2\right)-2\left(x+3\right)=-28\)

\(\Leftrightarrow4x-8-2x-6+28=0\)

\(\Leftrightarrow2x+14=0\)

\(\Leftrightarrow2x=-14\)

hay x=-7

Vậy: x=-7

b) Ta có: \(3x+7-9x=-11\)

\(\Leftrightarrow-6x+7+11=0\)

\(\Leftrightarrow-6x+18=0\)

\(\Leftrightarrow-6x=-18\)

hay x=3

Vậy: x=3