Đề đâu rồi bạn?

125 - (23 + 77) + (3x3) - (40+40) = 125 - 100 + 9 - 80

                                                     = 34 - 80

                                                     = -46

Goodluck!!

= 125 - 100 + 9 - 50

= 34 - 80 

= -46

\(125-\left(23+77\right)+\left(3\times3\right)-\left(40+40\right)\)

\(=125-100+9-80\)

\(=25+9-80\)

\(=34-80\)

\(=-46\)

_Chúc bạn học tốt_

\(3x^3-24\)

\(=3\left(\left(x-2\right)x^2+2\left(x^2-2x\right)+4\left(x-2\right)\right)\)

\(=3\left(x-2\right)\left(x^2+2x+4\right)\)

\(3x^3-24\\ =3\left(x^3-8\right)\\ =3\left(x^3-2^3\right)\\ =3\left(x-2\right)\left(x^2+2x+4\right)\)

\(\left|9-x\right|=2x\)

\(\Rightarrow\left[{}\begin{matrix}9-x=2x\\9-x=-2x\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=3\\x=-9\end{matrix}\right.\)

\(\left|x-15\right|+1=3x\)

\(\left|x-15\right|=3x-1\)

\(\Rightarrow\left[{}\begin{matrix}x-15=3x-1\\x-15=-3x+1\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=-7\\x=4\end{matrix}\right.\)

\(\left|5-4x\right|=4-5x\)

\(\Rightarrow\left[{}\begin{matrix}5-4x=4-5x\\5-4x=-4+5x\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=-1\\x=1\end{matrix}\right.\)

giúp em  bài với ạ,em cảm ơn, em đang vội ạ

\(a,=-15x^3+10x^4+20x^2\\ b,=2x^3+2x^2+4x-x^2-x-2=2x^3+x^2+3x-2\)

Đặt -4/3x^3+5x+4=0

=>-4x^3+15x+12=0

=>\(x\simeq2,25\)