Answer:

Step-by-step explanation:
Area = pi*r^2
Area = pi*9^2
Area = 
Answer:
Step-by-step explanation:
$ 6.18 is what each pen costs
3.643 x 10^3
move the decimal in between the first and second number
However many times you move the decimal, that is you exponent.
Answer:
tip total $4
tip per person $2
total (bill plus tip) $29.
total each person $15
Step-by-step explanation: