Question

[Nguyễn Thanh Huyền]

tìm x, biết (chú ý: m. phần cuối là 131-2 . (-5)  nha giúp em từ phần h-q đc khum ạ,

<3

Answer 1

[Nguyễn Lê Phước Thịnh]

h: \(\left(-145\right)-5\left(2x-1\right)^3=480\)

=>\(5\left(2x-1\right)^3=-145-480\)=-625

=>(2x-1)³=-125

=>2x-1=-5

=>2x=-5+1=-4

=>x=-4/2=-2

k: \(3\left(-4+x\right)^3-\left(-4\right)^2=-97\)

=>\(3\left(x-4\right)^3-16=-97\)

=>\(3\cdot\left(x-4\right)^3=-97+16=-81\)

=>\(\left(x-4\right)^3=-27\)

=>x-4=-3

=>x=-3+4=1

n: \(195+3\left(-2x+5\right)^3=192\)

=>\(3\left(-2x+5\right)^3=192-195=-3\)

=>\(\left(-2x+5\right)^3=-1\)

=>-2x+5=-1

=>-2x=-1-5=-6

=>\(x=\dfrac{-6}{-2}=3\)

o: \(\left(-148\right)-5\left(-x+6\right)^4=-228\)

=>\(148+5\left(x-6\right)^4=228\)

=>\(5\left(x-6\right)^4=80\)

=>\(\left(x-6\right)^4=16\)

=>\(\left[{}\begin{matrix}x-6=2\\x-6=-2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=8\\x=4\end{matrix}\right.\)

p: \(-43-\left(-4+x\right)^4=-44\)

=>\(\left(x-4\right)^4+43=44\)

=>\(\left(x-4\right)^4=1\)

=>\(\left[{}\begin{matrix}x-4=1\\x-4=-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=5\\x=3\end{matrix}\right.\)

q: \(3\left(-x+5\right)^2-\left(-5\right)^2\cdot\left(-2\right)^3=203\)

=>\(3\left(x-5\right)^2-25\cdot\left(-8\right)=203\)

=>\(3\left(x-5\right)^2+200=203\)

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

=>(x-5)²=1

=>\(\left[{}\begin{matrix}x-5=1\\x-5=-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=6\\x=4\end{matrix}\right.\)

Answer 2

[Akai Haruma]

h.

$(-145)-5(2x-1)^3=480$

$5(2x-1)^3=-145-480=-625$

$(2x-1)^3=-625:5=-125=(-5)^3$

$\Rightarrow 2x-1=-5$

$\Rightarrow x=-3$

k.

$3(-4+x)^3-(-4)^2=-97$

$3(-4+x)^3-16=-97$

$3(-4+x)^3=-97+16=-81$

$(-4+x)^3=-81:3=-27=(-3)^3$

$\Rightarrow -4+x=-3$

$\Rightarrow x=-3-(-4)=1$