Answer:
9/20
Step-by-step explanation:
In order to subtract fractions you need to find the least common denominator. Since the LCD is 20 (4 times 5 or 10 times 2) you need to multiply each fraction by 1 to get the denominators the same.
3/4 times 5/5 = 15/20
3/10 times 2/2 = 6/20
now you can subtract!
15/20 - 6/20 = 9/20
you can not simplify this, so your final answer is 9/20
