`1)x:(-1/3)^3=-1/3`
`→x=(-1/3).(-1/3)^3`
`→x=(-1/3)^4`
`→x=1/81`
Vậy `x=1/81`
`2)(4/5)^5 .x=(4/5)^7`
`→x=(4/5)^7:(4/5)^5`
`→x=(4/5)^2`
`→x=16/25`
Vậy `x=16/25`
`3)(x+1/2)^2=1/16`
`→(x+1/2)^2=(1/4)^2`
`→`$\left[\begin{matrix} x+\dfrac{1}{2}=\dfrac{1}{4}\\ x+\dfrac{1}{2}=-\dfrac{1}{4}\end{matrix}\right.$
`→`$\left[\begin{matrix} x=\dfrac{1}{4}-\dfrac{1}{2}\\ x=-\dfrac{1}{4}-\dfrac{1}{2}\end{matrix}\right.$
`→`$\left[\begin{matrix} x=-\dfrac{1}{4}\\ x=-\dfrac{3}{4}\end{matrix}\right.$
Vậy `x∈{-1/4;-3/4}`
`4)(3x+1)³=-27`
`→(3x+1)³=(-3)³`
`→3x+1=-3`
`→3x=-3-1`
`→3x=-4`
`→x=-4/3`
Vây `x=-4/3`
`5)(1/2)^2 .x=(1/2)^5`
`→x=(1/2)^5:(1/2)^2`
`→x=(1/2)^3`
`→x=1/8`
Vậy `x=1/8`
`6)(-1/3)^3 .x=1/81`
`→(-1/3)^3 .x=(-1/3)^4`
`→x=(-1/3)^4:(-1/3)^3`
`→x=-1/3`
Vậy `x=-1/3`
`7)(2x-3)²=16`
`→(2x-3)^2=4^2`
`→`$\left[\begin{matrix} 2x-3=4\\ 2x-3=-4\end{matrix}\right.$
`→`$\left[\begin{matrix} 2x=7\\ 2x=-1\end{matrix}\right.$
`→`$\left[\begin{matrix} x=\dfrac{7}{2}\\ x=-\dfrac{1}{2}\end{matrix}\right.$
Vậy `x∈{7/2;-1/2}`
`8)(x-2/3)^3=1/27`
`→(x-2/3)^3=(1/3)^3`
`→x-2/3=1/3`
`→x=1/3+2/3`
`→x=3/3`
`→x=1`
Vậy `x=1`
`9)(x+0,7)³=-27`
`→(x+0,7)³=(-3)³`
`→x+0,7=-3`
`→x=-3-0,7`
`→x=-3,7`
Vậy `x=-3,7`
`10)(2/3x-1/3)^5=1/243`
`→(2/3x-1/3)^5=(1/3)^5`
`→2/3x-1/3=1/3`
`→2/3x=1/3+1/3`
`→2/3x=2/3`
`→x=2/3:2/3`
`→x=1`
Vậy `x=1`
`11)(2/5-3x)^2=9/25`
`→(2/5-3x)^2=(3/5)^2`
`→`$\left[\begin{matrix} \dfrac{2}{5}-3x=\dfrac{3}{5}\\ \dfrac{2}{5}-3x=-\dfrac{3}{5}\end{matrix}\right.$
`→`$\left[\begin{matrix} 3x=-\dfrac{1}{5}\\ 3x=1\end{matrix}\right.$
`→`$\left[\begin{matrix} x=-\dfrac{1}{15}\\ x=\dfrac{1}{3}\end{matrix}\right.$
Vậy `x∈{-1/15;1/3}`
`12)(2x-1)^10=49^5`
`→(2x-1)^10=(7^2)^5`
`→(2x-1)^10=7^10`
`→`$\left[\begin{matrix} 2x-1=7\\ 2x-1=-7\end{matrix}\right.$
`→`$\left[\begin{matrix} 2x=8\\ 2x=-6\end{matrix}\right.$
`→`$\left[\begin{matrix} x=4\\ x=-3\end{matrix}\right.$
Vậy `x∈{4;-3}`
`13)x:5²=(3/5)^2:3^2`
`→x:5^2=(3/5:3)^2`
`→x:5^2=(1/5)^2`
`→x=(1/5)^2 .5²`
`→x=(1/5 .5)^2`
`→x=1²`
`→x=1`
Vậy `x=1`
`14)(x-3/5)^2=4`
`→(x-3/5)^2=2²`
`→`$\left[\begin{matrix} x-\dfrac{3}{5}=2\\ x-\dfrac{3}{5}=-2\end{matrix}\right.$
`→`$\left[\begin{matrix} x=2+\dfrac{3}{5}\\ x=-2+\dfrac{3}{5}\end{matrix}\right.$
`→`$\left[\begin{matrix} x=\dfrac{13}{5}\\ x=-\dfrac{7}{5}\end{matrix}\right.$
Vậy `x∈{13/5;-7/5}`
`15)(x-1/4)^2=4/9`
`→(x-1/4)^2=(2/3)^2`
`→`$\left[\begin{matrix} x-\dfrac{1}{4}=\dfrac{2}{3}\\ x-\dfrac{1}{4}=-\dfrac{2}{3}\end{matrix}\right.$
`→`$\left[\begin{matrix} x=\dfrac{2}{3}+\dfrac{1}{4}\\ x=-\dfrac{2}{3}+\dfrac{1}{4}\end{matrix}\right.$
`→`$\left[\begin{matrix} x=\dfrac{11}{12}\\ x=-\dfrac{5}{12}\end{matrix}\right.$
Vậy `x∈{11/12;-5/12}`
`16)(2x-5)^4=-81`
`text{→không có giá trị nào thỏa mãn x vì số mũ chẵn thì kết quả luôn dương}`
