y = 2x - 1.....the slope here is 2. A parallel line will have the same slope.
y = mx + b
slope(m) = 2
(4,2)....x = 4 and y = 2
now we sub and find b, the y int
2 = 2(4) + b
2 = 8 + b
2 - 8 = b
-6 = b
ur equation is : y = 2x - 6.....but we need it in standard form...
y = 2x - 6
-2x + y = -6 ...multiply by -1
2x - y = 6 <===