If they give you the total price and the price after the discount you can use this "formula" to solve it p/100=b/a where p is the percentage, a is the total price and b is the price after the discount.
Answer:
Your answer is D.
Step-by-step explanation:
If you need explanation ask me in comment
Answer:
-1/21
Step-by-step explanation:
2/3 + -5/7
Get a common denominator of 21
2/3 *7/7 = 14/21
-5/7*3/3 = -15/21
14/21 - 15/21 = -1/21