tolong jawab ya kak eliminasi nya aja

a. 2x +3y = 28 | ×3 = 6x +9y = 84
3x -4y = -9. | ×2 = 6x - 8y = -18 _
17y = 102
y. = 102/17 = 6

b. 7x -5y = 11. | × 3 = 21x - 15y. = 33
3x +4y =17 | × 7 = 21x + 28y = 119 _
43y = 86
y = 86/43 = 2

c. 6x + 7y = 32 | × 1 = 6x + 7y = 32
9x + y. = 29 | × 7 = 63x + 7y = 203 _
- 57x. = - 171
x. = -171/-57 = 3

d, 28m -15n = 41 |× 21 = 588m - 315n = 861
21m +13n = 55|× 28 = 588m + 364n = 1540 _
-679n = - 679
n = -679/ -679 = 1