Answer:
2
Step-by-step explanation:
2k+3=7
2k=4
k=2
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:
680 Bacteria
Step-by-step explanation:
378 is evenly divisible by 126, which is equal to 3.
The first 126 minutes, the 85 bacteria will double to 170 bacteria.
The second 126 minutes (252 minutes total), the 170 bacteria will double to 340 bacteria.
The final 126 minutes (378 minutes total), the 340 bacteria will double to 680 bacteria total.
If this helped, a brainliest would be greatly appreciated!
Answer:
the areas of these triangles are 83.2cm² and 46.8cm²
Step-by-step explanation:
1. If the triangles are similar and the ratio of the perimeter ois 4:3, then the areas are in the following ratio:
4²:3²
16:9
2. The sum of their areas is 65 cm², then, you can calculate the area of the larger triangle as following:
130(16/16+9)
130(0.64)
=83.2cm²
3. The area of the smaller triangle is:
130(9/16+9)
130(0.36)
46.8cm²
<u>Hope this help</u>s
Answer:
∠a = 10°
Step-by-step explanation:
The measure of ∠a = x
The measure of ∠b = 4x-30
It is also mentioned that the measure a and measure b are vertical angles. We need to find the value of a.
For vertically opposite angles,
∠a = ∠b
x = 4x-30
or
4x-30=x
Taking like terms together,
4x-x= 30
3x = 30
x = 10
So, the meausre of ∠a is equal to 10°.
