If you are asking how to subtract 125 centimeters and make it 87.5, you have to subtract from 125. The easiest way to do this is to subtract 87.5 from 125, getting 37.5. So, if you add 37.5 to 87.5, you will have 125. So, the correct answer is to subtract 37.5 to get 87.5.
A percent is a number out of 100, so you'd want to multiply the denominator to get 100. In this case, 25 would have to be multiplied by 4 to get 100. To keep the fractions equal to each other, you have to multiply the numerator by the same thing. 2*4=8. Therefore, your fraction would be 8/100 or 8%
Answer:
1. Not accounting for the difference in the base of the exponent when applying the quotient rule.
2. Not subtracting the exponents of the denominator from the exponent of the numerator when applying the quotient rule.
You would need to isolate the "X" variable because it is common in all 3 equations.