Explanation:
The given line y = 3x+1 has a slope of 3 as it is in the form y = mx+b
Any line parallel to this given line will also have a slope of 3. Parallel lines have equal slopes but different y intercepts.
Using m = 3 and (x,y) = (4,7), find the value of b
y = mx+b
7 = 3*4+b
7 = 12+b
12+b = 7
b = 7-12
b = -5
We have y = mx+b update to y = 3x+(-5) or y = 3x-5
Plug in x = 4 and you'll have y = 3x-5 turn into y = 7.