First you need to write the numerical equation for the given:

When you will simplify this fraction, you can divide the expressions. Based on the law of exponents when you divide like terms with different exponents, you can subtract the exponents of the denominator from the numerator.
So if you will simplify the equation:

Subtract the following:
Exponents of a 7-4 and;
Exponents of b 8-4
Your answer should be
Answer:
You would save $2.25.
Step-by-step explanation:
In order to find discount on an item, you need to multiply the discount by the original amount of the item. In this case, the cake you want regularly costs $9. If the sale includes a 25% discount, then you need to first convert your percentage to a decimal by dividing by 100:

You can then take this amount multiplied by the original cost of the cake to get your discount:
0.25 x 9 = 2.25, so you would save $2.25 with the discount and pay only $6.75 for the cake you want.
Answer:
Step-by-step explanation:
it is adding or subtrating