The answer is 45 because 45-15=30, therefore x=45.
Set up the following equations:
x represents the amount of blue books needed, and y represents the amount of red books needed.
Solve the first equation by dividing both sides by 9:
Rebecca would need 61 pages if she used the blue book.
Solve the second equation by dividing both sides by 7:
Rebecca would need 78 pages if she used the red book.
Subtract the red book's pages from the blue book's pages:
Rebecca would need
17 more pages if she used the red book instead of the blue book.
Use the formula for finding the midpoint
A) 2√3
B)3√3
C)5√2
Because radicals multiply like rational numbers