Question

I need help but you need to show me your steps.
3/4 - 15/21 =?
3/4 - 5/12 =?
4/5 - 2/11 =?
3/7 - 11/28 =?

Answer 1

okay so you find the lowest common denomiator btw 4 and 12
which is 12. 4x3=12 and 3x3=9, you have to multiply by the same number for the top and the bottom. so you get 9/12-5/12 then subtract 9-5=4 so the answer is 4/12 or 1/3