Question

Find the equation of the line that passes through (4, 5) with a slope of 2.

Answer 1

There is a couple of ways to do this...
either by using the point-slope formula, or you can also use y = mx + b form.
Which one do you want to use ?

Answer 2

y=mx+b

Answer 3

ok
(4,5) x = 4 and y = 5
slope(m) = 2
now we sub

y = mx + b
5 = 2(4) + b
5 = 8 + b
5 - 8 = b
-3 = b

your equation is : y = 2x - 3

Answer 4

so basically, when you plug in your stuff, you are looking for b, which is your y intercept.
If you were to use point-slope formula : y - y1 = m(x - x1) and solved for y, you would get the same answer