a) x=52-32 => x=20
b) x-394=11² unde 11²=121 => x-394=121 => x=121+394 =>x=515
c)x:12=81 => x= 81 X 12 => x = 972
d) 2x+39=125 => 2x=125-39 => 2x=86 => x = 86 : 2 => x=43
e) 234-3x=81 => -3x = 81-234 => -3x = -153 => x = -153 : (-3) => x = 51
f)134+ 8 ( x+5) + 230 => 134 + 8x+40=230 =>8x=230-134-40=> 8x=56=> x=7
g) [(x-2) x 3 + 5 ] : 2 = 13 => (3x-6+5) : 2 = 13 => 3x-1 supra 2 = 13 => 3x-1 = 13 × 2 => 3x= 26+1 => 3x= 27=> x=9