Réponses

2014-09-30T18:10:54+02:00
1728 - 18x = 3 * 18x
⇔ 1728 =  4 * 18x
⇔ 1728 = 72x
⇔ x =   \frac{1728}{72}
⇔ x = 24
2014-09-30T18:23:58+02:00
1728 - 18x = 3 * 18x 
⇔ 1728 = 3 * 18x + 18x
⇔ 1728 = 18x * (3  + 1)
⇔ 1728 = 18x * 4
⇔ 1728 = 72x 
 x =  \frac{1728}{72}
⇔ x = 24