Answer:
9
Step-by-step explanation:
2*2=4*2=8+2=10-1=9
Answer:

Step-by-step explanation:
we know that
Heron's Formula is a method for calculating the area of a triangle when you know the lengths of all three sides.
so

where
a, b and c are the length sides of triangle
s is the semi-perimeter of triangle
we have

<em>Find the semi-perimeter s
</em>
s=
Find the area of triangle



simplify

The answer is 7^4 / 3^10.
8^15 ÷ 1/8^3 = 8^15 x 8^3=8^18
1st ring=$50
2nd ring=$37.50
3rd ring=$25
$50+$37.50+$25 =$112.50 total cost before tax
$112.50 X 1.08=$121.5 total cost and tax
3 X $50 X 1.08=$162 total cost without discount deal
$162 - $121.50 =$40.50 savings