Đáp án:
5 . (x - 2) + 135 = 5² . 3²
5 . (x - 2) + 135 = 25 . 9
5 . (x - 2) + 135 = 225
5 . (x - 2) = 225 - 135
5 . (x - 2) = 90
x - 2 = 90 : 5
x - 2 = 18
x = 18 + 2
x = 20
Vậy x = 20
12 . (x - 1) : 3 = 4³ - 2³
12 . (x - 1) : 3 = 64 - 8
12 . (x - 1) : 3 = 56
12 . (x - 1) = 56 . 3
12 . (x - 1) = 168
x - 1 = 168 : 12
x - 1 = 14
x = 14 + 1
x = 15
Vậy x = 15
(3x - 2³) . 5² = 250
(3x - 8) . 25 = 250
3x - 8 = 250 : 25
3x - 8 = 10
3x = 10 + 8
3x = 18
x = 18 : 3
x = 6
Vậy x = 6
7 x - x = 5² + 3 .2² -1
7.x - x.1 = 25 + 3 . 4 -1
(7 - 1) . x = 25 + 12 - 1
6 . x = 36
x = 36 : 6
x = 6
Vậy x = 6
$(x - \frac{1}{2})^{3}$ = $\frac{1}{27}$
$(x - \frac{1}{2})^{3}$ = $(\frac{1}{3})^{3}$
⇒ `x` `-` `\frac{1}{2}` = `\frac{1}{3}`
⇒ `x` = `\frac{1}{3}``+` `\frac{1}{2}`
⇒ `x` = `\frac{5}{6}`
Vậy `x` = `\frac{5}{6}`
`\frac{1}{2}` `-` `2x` = `(``\frac{-1}{2}``)`
`2x` = `\frac{1}{2}` `-` `(``\frac{-1}{2}``)`
`2x` = `1`
`x` = `1` : `2`
`x` = `0,5`
Vậy `x` = `0,5`
