I can help you with #20. For example, lets say 3/5, this fraction would be made up of 5 parts and 3 are covered, which doesn't make it full, if it was 5/5 it would be full. When you do something with a reciprocal you turn it over, so 3/5 would be turned over to 5/3, thus making it a whole number
First we need to find 75% of $450, so 450x.75=337.5
to find the markup we have to add 450+337.5 to get $787.5.
X= -3B + 2A
= [ 9 21 ] + [ 8 -2 ]
-21 -3 10 4
comparing the corresponding elements,
X= [ 9+8 21-2]
-21+10 -3+4
X= [17 19 ]
-11 1
Answer: I believe the answer is D.
Step-by-step explanation:
I agree with ZOMBIE0O That the question is somewhat confusing. I see two options as being possible, depending on the nature of the question. The first option, 49, is a possibility. This would be the answer if the second two numbers were insignificant to the number of books (for example, if it were describing the dimensions of the books as 5•40). The second option is also a possibility, if the question is wanting you to add (49•5)+(5•40).