Question 64997
2/5 are red, 2/7 are green, & the rest are blue

The blue marbles=1-(2/5+2/7)

The lowest common multiple for 7 and 5 is 35 so we multiply everything by 35/35 and we get:


The blue marbles=35/35-(2/5)(35/35)-(2/7)(35/35) simplifying, we have:

The blue marbles=35/35-((2)(7))/35-(2)(5))/35 further simplifyinig:

The blue marbles=35/35-14/35-10/35=

The blue marbles=(35-24)/35=11/35

11/35 is the fraction of the marbles that is blue


CK
35/35=11/35+2/5+2/7
35/35=11/35+14/35+10/35
35/35=35/35 or
1=1


Hope this helps.  Happy holidays----ptaylor