I am gonna do what you did to me and say its easy.
Let x be a variable.
Using the ratio and the given number of 117, we can create the following formula:
1x + 3x + 9x = 117, where 3x is the cups of onion
Simplify this equation.
13x = 117
Divide both sides by 13
x = 9
We want to solve for 3x, so multiply both sides by 3
3x = 27
As I started earlier, 3x is how many cups of onions is needed; thus, 27 is our answer. Hope this helps! :)
The exponent for that would be 13^3.
If the answer is incorrect, then i am sorry.
30% off 25: multiply 25 by .30 to find 30%: 7.5. Now subtract that from the sales price: 25-7.5=17.5
Do the same for store B: .40•30=12. 30-12=18.
So store A is better by $.50 :) hope this helps :)