3х – у = 9 ......................... equ 1
- 3х + 5у = -3 ......................equ 2
equ 1 + equ 2 :
3x + -3 x - y + 5y = 9 + -3
4y = 6
Divide both sides by 4, we have:
y = 6/ 4= 3/ 2 = 1.5
Put y = 3/2 in equ 1, we have
3 x - y = 9 ,
3x - 3/2 =9,
3x = 9 + 3/2
3x = 18/2 + 3/2 = 21/2
3 x = 21/2
Divide both sides by 3,
x = 21/6 = 7/2 = 3.5
Conclusion : x = 3.5
y = 1.5