Step 1. Simplify

to

Step 2. Simplify

to

Step 3. Simplify

to

Step 4. Cancel

on both sides
Step 5. Multiply both sides by

(the LCM of

)
Step 6. Expand
Step 7. Subtract

from both sides
Step 8. Simplify

to

Step 9. Multiply both sides by


Done! :) Hope this helps! :)
So in total, there are 7 marbles, (3 black + 4 red = 7 total marbles) and we want to find out how much black marbles are able to come out. So it would be 3/7. :)
x
905 whatever that is (I forgot)
36/5 will be simplified 144/20
Well, first of all, LCM means Lowest Common Multiple. So you have to write out the factors of each of the numbers. So that will be;
2= 2, 4, 6, 8, 10, 12, 14, 16, 18, 20
5=5, 10, 15, 20
So now, you have to pick out the numbers that are common to both numbers. So;
10, 20
10 and 20 are the only common numbers. So you have to look for the lowest common number. And that is 10. So the LCM is 10.. Hope i helped. Have a nice day.