Svpbesoib exercice je vois en suplie

bonsoir

4 x - 9 y = 5
2 x + 6 y = 7

4 x - 9 y = 5
- 4 x  - 12 y  = - 14

- 21 y = - 9
y = 9/21 = 3/7

4 x - 9 y = 5
4 x - 27/7 = 5
4 x = 5 + 27/7
on met sur 7
28 x = 35 + 27
28 x = 62
x = 62/28 = 31/14

on vérifie

4 x - 9 y = 5
4 ( 31/14) - 9 ( 3/7) = 5
124/14 - 27/7 = 5
124/14 - 54/14 = 70/14
124 -54 = 70
70 = 70