If you already have the x and y intercepts, you can use a formula to figure the equation out
$${x\over a}+{y\over b}={1}
$$
"a" would be the x intercept and "b" would be the y intercept
$${x\over 1.5}+{y\over -3}={1}
$$
multiply 2 on the top and bottom of
$${x\over 1.5}
$$
So you get
$${2x\over 3}
$$
Then using this info we get
$${2x\over 3}+{y\over -3}=1
$$
$${2x-y\over 3}=1
$$
$${2x-y}=3
$$
After rearranging things, we get
$$y={2x-3}
$$
And that's it!
