Answer:
sin Φ/(sin Φ + cos Φ) = 12/17
Step-by-step explanation:
sin Φ = 12/13
then sin Φ + cos Φ = 12/13 + 5/13
= 17/13
So , sin Φ/(sin Φ + cos Φ) = 12/13 ÷ 17/13
= 12/13 × 13/17
= 12/17