First, let's multiply both sides by 10 to get nice whole numbers.
10(-2.7y+4.5x+1.8)=10(0)
-27y+45x+18=0
Subtract both sides by 18 to get one side with variable and one side without.
-27y+45x=-18
Divide both sides by 3 since all three terms are divisible by 3.
-9y+15x=-6
Repeat previous step again.
-3y+5x=-2
Subtract both sides by 5x to get y on one side.
-3y=-5x-2
Divide both sides by -3 to get y alone.
y=(3/5)x+2/3
Now you know the line has a y intercept at (0,2/3) and a slope of 3/5.