Answer:
7 paperbacks, 2 hardcovers
Step-by-step explanation:
2x8=16
7x5=35
35+16=51
Hope this answers your question.

Which of the following is not a linear equation in one variable?
a) 33
b) 33(x+y)
c) 33x
d) 33y

- Option <em><u>b) 33 (x + y)</u></em> is not a linear equation in 1 variable.
- Here, we can see that there are 2 variables used ⇨ x & y. Hence, even though it's a linear equation, it's not in 1 variable.
- All the other options are in 1 variable or don't have a variable at all.
Population density (people per square mile) is found by dividing population by square miles. The appropriate numbers are found in choices A and B, but only choice B uses the <em>divided by</em> operation.
The appropriate choice is ...
... B) 1.2e6÷1.1e4
The number is 1
1 + 1 = 2
2(2) = 4
1 is your answer
hope this helps