2/5 and 1/2 can go into 10.
So, 2/5*2 = 4/10
and, 1/2*5 = 5/10.
Got it?
Answer:

Step-by-step explanation:
First draw a line. I will put it in an attachment so you can see the line.
Now choose to points on the line to use the slope formula.
(0,15) and (3,13).
Slope formula: 
Plug in the information needed using the two points chosen.

The slope is
.
Now use point-slope formula.
Point-slope formula: y-y1=m(x-x1)
y-15=
(x-0)
y-15=
x-0
Subtract 15 from both sides.
y=
x-15
Hope this helps!
If not, I am sorry.