Please help me out! :)

You can simplify the left hand side:
[tex]\dfrac{7}{5} = \dfrac{y+9}{15}[/tex]
Multiply both sides by 15:
[tex]3\cdot 7 = y+9 \iff 21=y+9[/tex]
Subtract 9 from both sides:
[tex]y = 21-9=12[/tex]
Answer:
y = 12.
Step-by-step explanation:
Cross multiplying:
10(y + 9) = 14*15
10y + 90 = 210
10y = 120
y = 12 (answer).