Assuming your fraction is 12/45, You start by finding the common division factors.
12 can be divided by 2, 3, 4, 6, and 12
45 can be divided by 3, 5, 9, 15, and 45
since both can be divided by 3, you divide both the numerator (top) and denominator (bottom) by 3 leaving you with:
4/15
Since 4 and 15 do not have any common factors, that is the simplified answer of 12/45
4b-5 simplifyed = -1
63/100.
9/15 is simpliflyto
3/5
You can't simplify a decimal.
7/20
3bc
31/100
2/5
9/10
1/8
4/9