Answer: 
Step-by-step explanation:
Given
Equation is 
Mila uses the first step as multiplication to make the coefficient of x, 1
Mila maybe have multiplied the whole equation by 2 i.e.

Answer: They collected 13,204 cans more than needed.
Keep the denominators the same and subtract the numerators. So for example in your example:
7/8 - 3/8
Leave the 8 alone. Subtract 3 from 7.
7 - 3 = 4
So answer is:
4/8
Sometimes they may have to simplify the answer, and in this case, 4/8 could be simplified to 1/2
We know that
<span>1½ cup of cleaner-------> (1*2+1)/2-----> 3/2 cup of cleaner
</span><span>the ratio of cleaner to water=(3/2)/12---> 3/(2*12)--> 3/24--> 1/8
the answer is
1/8</span>