Rename 1/6 and 7/15 using the least common denominator

ok so LCM of 6 & 15 is 30...

 

30/6=5 so 1/6 = 5/30 (you must multiply the numerator and denominator by the same value to keep it in ratio)

&

30/15 = 2 so 7/15 = 14/30

 

so the answers are 1/6 = 5/30 and 7/15 = 14/30