If those are all denominators, the LCD is 360.
A common denominator is 72.
120
72
120
The Greatest Common Denominator is 6
21/24 and 20/24
21/24 and 20/24
The common denominator is 72, so 5/18 = 20/72, and 7/24 = 21/72. Now you can subtract the numerators [20-21 = -1]. So the answer is -1/72.
The Least Common Multiple (LCM) for 18 24 20 is 360.
For 18 and 56: 504 For 1/8 and 5/6 : 24
The LCD of 1/3 and 1/8 is 24.
The fraction 20/24 can be reduced by finding the greatest common divisor (GCD) of the numerator and denominator. The GCD of 20 and 24 is 4. Dividing both the numerator and the denominator by 4, we get 5/6. Thus, 20/24 reduced is 5/6.