\(\left(15-5x\right)^3=-125\)
\(\Rightarrow\left(15-3x\right)^3=\left(-5\right)^3\)
\(\Rightarrow15-3x=-5\)
\(\Rightarrow3x=20\)
\(\Rightarrow x=\frac{20}{3}\)
Vậy\(x=\frac{20}{3}\)
\(\left(15-5x\right)^3=-125\)
=> \(\left[5\left(3-x\right)\right]^3=\left(-5\right)^3\)
=> \(5\left(3-x\right)=-5\)
=> \(3-x=-1\)
=> \(x=4\)
(15-5x)^3=-5^3
15-5x =-5
5x =20
x =4
Ta có : \(\left(15-5.x\right)^3=-125\)
\(\Leftrightarrow\) \(\left(15-5.x\right)^3=\left(-5\right)^3\)
\(\Leftrightarrow\) \(15-5.x=\left(-5\right)\)
\(\Leftrightarrow5.x=15-\left(-5\right)\)
\(\Leftrightarrow5.x=20\)
\(\Leftrightarrow x=20:5\)
\(\Leftrightarrow x=4\)
Vậy \(x=4\)
Study wel !
Xl mình làm nhầm, mấy bạn kia làm đúng rồi đó
