Answer:
Step-by-step explanation:
*
*
*
because the bases are all the same.. just add the exponents

or

21 + 15 = 36
36 x 3 = 108
Their father donated $108 to charity
Greetings!
"<span>The circumference of a circle is 12 inches. What is the radius?"...
We can use the formula to find the circumference of circle to solve this:
</span>

<span>
Input the information we know:
</span>

<span>
Solve for
r, using the properties of equality:
Simplify.
</span>

<span>Divide both sides by
6.28</span>

<span>
Simplify.
</span>

The radius is
1.91cm long.
Hope this helps.
-Benjamin