The smallest multiple 3 and 9 have in common is 9.
2/3 becomes 6/9 and 5/9 does not change
3k/40 +k/18 factoring 40=2*2*2*5 18=2*3*3 LCD=2*2*2*5*3*3 LCD=360
24: 2 * 2 * 2 * 3 30: 2 * 3 * 5 LCD is 2^3 * 3 * 5 = 120
45
15
1440
3k/40 +k/18 factoring 40=2*2*2*5 18=2*3*3 LCD=2*2*2*5*3*3 LCD=360
10
LCD(3, 5, 4, 2) = 60
The LCD is 30.
15.
2/3 and 3/4Looks like 12 here, so use form of one to convert both fractions to LCD form.4*2/4*3 and 3*3/3*48/12 and 9/12==========
LCD(2, 5, 6, 3) = 30
24: 2 * 2 * 2 * 3 30: 2 * 3 * 5 LCD is 2^3 * 3 * 5 = 120
45
48
3
It is: 12