Doing (2x-5) first is what
Each group of 2 nickels and 1 quarter has a value of $0.35. Rachelle has $6.30/$0.35 = 18 such groups.
Rachelle has 18 quarters and 36 nickels.
6.9
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When two fractions have the same denominator, you can compare which fraction is greater by just comparing the numerators.
For example, if you have 2/5 and 3/5, the denominators are the same. So you can just look at the numerators. 3 is greater than 5, so 3/5 is greater than 2/5.
The reasoning to this is that the two numbers are divided by the same number (5), so you can compare the original numbers (numerators).
To find the answer, multiply the decimal by 10. 0.05 X 10 = 0.5, and since 0.05 goes into 0.5 10 times, it is equivalent to 1/10th of 0.5.