Question

write an equation of a line parallel to the line y=2x+7 and passing through the point (4,2)

Answer 1

y = 2x + 7
y = 2(4) + 7
y = 8 + 7
y = 15

y = 2x + 7
2 = 2x + 7
-7          -7
-5 = 2x
 2      2
-2.5 = x

(x y) = (-2.5, 15)

Answer 2

y=mx+b
lines are parallels so m=2

y=2x+b
 line passing through the point (4,2), so x=4 y=2
put these value in equation
2=2*4+b
2=8+b
b=2-8
b=-6
y=2x-6
Answer: y=2x-6

(verification on the picture)