How do you find the LCD for #\frac { - 11} { 20}# and #\frac { 13} { 50}#?
1 Answer
Jul 2, 2017
Find the multiples of 20 and 50 and see which ones they have in common. The smallest one is the LCD. In this case, 100.
Explanation:
20: 20, 40, 60, 80, 100, 120, 140, 160, 180, 200
50: 50, 100, 150, 200
100 and 200 are common multiples
CD is a common denominator for a and b
BUT
this is the same as a CM common multiple of a and b
The LCD is the L - Lowest of these common multiples
