please jawab no 9 dengan caranya

(x+7)/6 - 1 = (2y-25)/5
((x+7)-6) / 6 = (2y - 25)/ 5 ....(angka 1 dijadikan 6/6 agar sama penyebutnya )

(x+1) / 6 = (2y -25) /5
5(x+1) = 6(2y-25)
5x+5 = 12y -150
5x-12y = - 155

(8x-4)/9 +3 = (y-1) / 2
(8x-4)+27) /9 = (y-1) /2
(8x + 23) / 9 = (y-1) /2
2(8x+23) = 9(y-1)
16x +46 = 9y -9
16x -9y = -55

eliminasi y
5x - 12y = -155 |9|
16x - 9y = -55 |12|
45x - 108y = -1395
192x - 108y = -660
_______________-
-147x = -735
x = 5
sub x = 5 ke 16x -9y =-55
16(5) -9y = -55
80 -9y = -55
9y = 80 +55
9y = 135
y= 15

x = 5 y = 15 hasil dari a+b = 5+ 15 =20

koreksi lagi jawabannya

a.20 #maaf kalo salah