Answer:
70
Step-by-step explanation:
The formula for calculating the area of a circle is expressed as;
A = πr²
- Area of the pond = πr²
- Area of the path = Area of the path + pond - area of pond
- Area of path = π(r+1.5)² - πr²
Since the area of the path is equal to the area of the pond, hence;
π(r+1.5)² - πr² = πr²
Add πr² to both sides
π(r+1.5)² - πr² + πr² = πr² + πr²
π(r+1.5)² = 2πr²
(r+1.5)² = 2r²
Expand the parenthesis
r²+3r + 2.25 = 2r²
r²+3r + 2.25 - 2r² = 0
-r² + 3r + 2.25 = 0
r² - 3r - 2.25 = 0
Multiply through by 2
2r² - 6.0r - 4.5 = 0
<em>This proves the required equation</em>
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Learn more on area of composite figures here: brainly.com/question/15981553
Answer:
£0.465. It is a better value.
Step-by-step explanation:
If a pack of 6 batteries costs £2.79, price of a battery can be calculated as shown;
6batteries = £2.79
1 battery = x
x = cost of a battery
6x = £2.79
x = £2.79/6
x = £0.465
Price per battery will be £0.465. This price is a better value since the price is lesser than the cost of the 6batteries (£2.79) in a pack.
Answer:
salary=120000
1/4×120000=30000= money spent
remainder=120000- 30000
= 90000
money spent on clothing =1/2×90000
=45000
12 x 180 is equal to 2160. It would cost $2160