3x + 5y = 15
5y = -3x + 15
y = -3/5x + 3....slope = -3/5. A parallel line will have the same slope.
y = mx + b
slope(m) = -3/5
(2,3)...x = 2 and y = 3
now we sub and find b, the y int
3 = -3/5(2) + b
3 = -6/5 + b
3 + 6/5 = b
15/5 + 6/5 = b
21/5 = b
so ur parallel equation is : y = -3/5x + 21/5