2x-7y=35 5x+3y=26 Nilai dari 3x - 4y adalah???

2x-7y=35|×3
5x+3y=26|×7

6x-21y=105
35x+21y=182
6x-21y+105-35x+21y-182
29x=77
x=2,65=3

2x-7y=35
2×2,65-7y=35
5,30-7y=35
-7y=29,70
y=-4,24

3x-4y=3×2,65-4×-4,24
=7,95+16,96=24,91