Find the equation of the line

With a slope of 2/3 that goes through the point (4, 5)

y=mx + b you are given m, slope.

y=2/3 x + b
Now to find the specific equation, put in x,y
5=2/3 *4 + b
solve for b.
b=5- 8/3

so the equation is ...
y=2/3 x + 5 - 8/3
most kids would combine the last two terms.