To solve:
Since 8 does not fit into 20 and both fractions are in simplest form, we would increase the fraction with the largest denominator (20), and in this case, by 2 times.
20*2=40
Eight fits into 40 (8*5), meaning that 40 is the least common denominator of 5/8 and 13/20.
Answer: The LCD is 40
*Btw, the two fractions would be 25/40 and 26/40
