himpunan penyelesaian dari sistem persamaan 3x + 4y = 17 dan 5x + 7y = 29 adalah ..... (pake cara substitusinya aja)

3x = 17-4y
x = (17-4y)/3

5x+7y = 29
5(17-4y)/3 +7y =29
(85-20y)/3 +7y =29
(-20y+21y)/3 = 29-85/3
y/3 = (87-85)/3
{y/3 = 2/3} (x3)
y = 2

5x+ 7y = 29
5x + 7(2) = 29
5x + 14 =29
5x = -14+29
5x = 15
x = 3

x=3 y=2
maaf kalau salah