$\text{f,}$ `7. (x-1) = 6 . (x+5)`
$\Leftrightarrow$ `7x - 7=6x +30`
$\Leftrightarrow$ `7x - 6x=7+30`
$\Leftrightarrow$ `x=37`
$\text{Vậy x=37}$
-----------------------------------
$\text{g,}$ `25 . x^{2} = 24 . 6`
$\Leftrightarrow$ `25 . x^{2} = 144`
$\Leftrightarrow$ `x^{2} = 144 : 25`
$\Leftrightarrow$ `x^{2} =` `144/25`
$\Leftrightarrow$ `x =` `12/5`
$\text{Vậy x =}$ `12/5`
