5.3-1.5x=1.1 is solved by getting the unknowns on side of the equation and the knowns on the other. We do this by adding or subtracting quantities from either side of the equation. If we add 1.5x to each side we can get rid of the negative sign: 5.3=1.1+1.5x. Now subtract 1.1 from each side: 4.2=1.5x. Don't like decimals? Multiply both sides by 10 so the the decimal point is removed: 42=15x. Both sides can be divided exactly by 3, because 3 goes into 42 and 15: 14=5x. This equation is exactly the same as 5x=14. We have to divide both sides by 5 to leave x by itself, but 5 doesn't go into 14 exactly, so we need to go back to decimals: x=2.8. This is obtained by dividing 5 into 14.0. 5 goes out not 14 twice with 4 over, which makes 40 with the zero just added. The result is 8 but it's after the decimal point, hence the answer 2.8.