If starting out, there are 100 marbles and Zoe pulls out a 5 and doesn't replace it, then there are 99 marbles left to choose from. So, there are 9 digits 1-10 (not including #5) making the proportion you have left 9/99 which simplifies to 1/11
The real way is to subtract the term with the variable on the right first, but both Spencer and Jeremiah are correct. When you do them both, they arrive at the same answer, only that Spencer's would be 2/5, and Jeremiah's would be -2/-5, which is 2/5, because you divide negative by a negative. It doesn't matter which term with the variable you would cancel out first. Either way, you still arrive at the correct answer.
Answer:
5807259.34663
Step-by-step explanation:
Calculator! Yeah!
Hope this helps!