tentukan nilai y berikut agar memenuhi perbandingan senilai 39:91=(y+1):7

[tex] \frac{39}{91} = \frac{y+1}{7} [/tex]
[tex] \frac{39 :13}{91 : 13} = \frac{y = 1}{7} [/tex]
[tex] \frac{3}{7} = \frac{y + 1}{7} [/tex]
Maka otomatis :
3 = y +1
y = 2