The slope intercept form of an equation is given as
y = mx + b
where b is the y intercept and m is the slope.
So you already have
y = mx + 5
You can find the slope of the line by using two points and the slope formula. You have two points -- the x intercept (3,0) and the y intercept (0,5). So now you can find the slope of the line by using
m = y1-y2/x1-x2
m = (5-0)/(0-3)
That will give you your slope and then you have the equation.
Pay attention, if it is given the value of x intercepting point, that means that y = 0.
This point is on the line y = mx + n, that represents the slope intercept form.
The point (3 ; 0) is located on a line if and only if it's coordinates verify the equation of the line:
0 = 3m + n (1)
If it is given the value of y intercepting point, that means that x = 0.
The point (0 ; 5) is located on a line if and only if it's coordinates verify the equation of the line:
5 = 0*m + n
n = 5 (2)
We'll substitute n in (1):
0 = 3m + n
3m = -n
m = -n/3
m = -5/3
The slope intercept form of the line is:
y = -5x/3 + 5
Thats a great answer... I am high school shopmore and just started these topics. I actually found a cool site which even has slope calcualtors....it might help you.