Option A is the correct answer
2j+5=21
2j=16
j=8
<span>Jack is 8 years old.
</span>
Hope This Helped! :3
~Hello There!~
The formula to find the area of a circle is:

We already know this answer, so we write it as:

We need to calculate the radius (r) from this so divide both sides by 

Square root this to get r
r = 3.949327085
The formula for circumference is 
(d is the diameter )
Double the radius to get the diameter:
d = 7.89865417
Multiply this value by
to get the answer
The circumference is 24.81435391
Hope This Helps You!
Good Luck :)
Have A Great Day ^_^
- Hannah ❤
Answer:
$3450
Step-by-step explanation:
The cost of one computer is the sum of the cost of the parts:
$120 +100 +45 +30 +50 = $345
Then the cost of 10 of them is ...
10 × $345 = $3450 . . . . cost for 10 computers
Answer:
Multiply the 8 by 5
Step-by-step explanation:
8÷1/5
Copy dot flip
8 * 5/1
40