Urgen svp ilfaut resoudre les equation qui sont a 2 inconnues

a-
2x+6y=5   
3x-4y=1

3x-4y=1
3x=1+4y
x=1/3 +4y/3

2(1/3 +4y/3)+6y=5 
2/3 +12y/3 +6y=5
(12y+18y )/3 = 5 -2/3
30y/3=(15-2) /3
10y=13/3
y=13/30

x=1/3 + 4/3 * 13/30
x=1/3 +  52/90
x=30+52 /90
x=82/90
x=41/45

b-
4x+8y=2   
x-4y=5
 
x-4y=5
x=5+4y

4(5+4y)+8y=2
20+16y+8y=2
24y=2-20
y=-18/24
y=-3/4

x=5+4  *(-3/4)
x=5-3
x=2

2 x + 6 y = 5
3 x - 4 y = 1

6 x + 18 y = 15
- 6 x + 8 y = - 2

26 y = 13
y = 0.5

3 x - 4 (0.5) = 1
3 x - 2 = 1
3 x = 1 + 2
3 x = 3
x = 1
vérification

2 x + 6 y = 5
2 + 3 = 5