The area of a circle is approximately 3.14 times the radius squared. Which of the following expressions is a correct way to write this, if the radius is x?
Merrill bought m CD's for $12.50 each and n greeting cards for $1.95 each. Which expression best shows how much she spent?
A. 12.50m + 1.95n
B. 12.50 + m + 1.95 + n
C. 14.45(m + n)
D. mn + (12.50)(1.95)