-5x/7+23=21 résoudre l'équation
-5x/7 + 23 = 21
-5x / 7 = 21 - 23
-5x/7 = - 2
-5x = -2 *7
-5x = -14
x = -14 / (-5)
x = 14/5
-5x/7 = 21-23
-5x/7 = -2
-5x = -2X7
-5x = - 14
x = -14/-5 donc 14/5
