You can put this solution on YOUR website! When subtracting and adding fractions you need to have LCD;
ex; -=
You need to have common denominators first; let's make it 15;
so what times 5 = 15; 3, so you multiply the numerator by 3; =
What times 3 = 15; 5, so we multiply the numerator by 5; =
Now that we have LCD we can subtract, you only subtract the numerators; -=-
hope you understand
=)