Hi the answer to your question is
((3y - 3.5) / (3y + 6)) * 25.5 = (17 / 25.5) * 25.5
((3y - 3.5) / (3y + 6)) * 25.5 = 17 (76.5y - 89.25) / (3y + 6) = 17
((76.5y - 89.25) / (3y + 6)) * (3y + 6) = 17 * (3y + 6) 76.5y - 89.25 = 51y + 102 76.5y - 51y = 102 + 89.25
25.5y = 191.25
y = 191.25 / 25.5
y = 7.5