Bonsoir,
2-1 = 1
2*2 + 3*1 =
4 +3 =7
x= 1-y
2(1-y) +3y = 4
2- 2y +3y =4
3y-2y = 4-2
y = 2
x+2 = 1
2-1 = x
1 = x
