y + 3x = 9
y = -3x + 9....the slope here is -3. A parallel line will have the same slope.
y = mx + b
slope(m) = -3
(2,7)....x = 2 and y = 7
now we sub into the formula and find b, the y int
7 = -3(2) + b
7 = -6 + b
7 + 6 = b
13 = b
so ur parallel equation is : y = -3x + 13 <==