The decrease was 27%.
Step-by-step explanation:
Old value = $980
New value = $720
Decrease = Old value - New value

Percent decrease = 

Rounding off to near whole percent
Percent decrease = 27%
The decrease was 27%.
Keywords: Percentage, subtraction
Learn more about subtraction at:
#LearnwithBrainly
The answer is A.) 21x/^3y
Here is proof
18.75÷5=3.75
12.75÷3=4.2
The pack of 5 books has the lower cost per book
X=5+(p+a). I think thats right idk tho
2.134 x 10^4 is equal to 21,340