Circumference = 2 x radius x Pi
Circumference = 2 x 15 x 3.14
Circumference = 30 x 3.14
Circumference = 94.2 feet
Answer:

Step-by-step explanation:
we have the expression:

To factor this expression we need to indentify the components that are common in both terms.
At first glance there is nothing in common, but we can notice that 30 and 70 are multiples of 10, that is:

so we can substitute this into the expression:

and now that we have the common term (the number 10) we can factorize it, that is, take out the common term and include a parentheses:

Answer:
(49 - 29) + 1 =(50 - 29)
Step-by-step explanation:
The 20 comes from the subtraction of 29 in both sides of the previous step equality. In the following, I transcript the complete procedure and I add the step that you need to understand why 20 appears (in bold numbers):
29+20=49
49+1=50
(49 - 29) + 1 =(50 - 29)
20+1=21
50-29=21
hence, it was only nesseraty to subtract 29
Answer:
2006 years old.
Step-by-step explanation:
If it had 50% of its carbon-14 it would be 5730 years old.
Since it has 65% left it is younger than 5730 years.
So it is (1 - 0.65) * 5730
= 2005.5 years old.