Aline crosses the y-axis at the point (0, 3) and passes through the point (4, 5). which of the following is an equation of the line?

The slope intercept form of a straight line is

y = mx + c where m = slope and c = y-intercept

so here we have c = 3.
and
y = mx + 3
WE can find the slope  m as follows
m  = (5-3) / ( 4 - 0) = 2/4 = 1/2
So our equation is

y = 1/2 x + 3
or we could write it as
2y = x + 6
or
-x + 2y = 6  (standard form)