<em>d = 2r => r = d/2 = 15cm/2 = 7,5 cm</em>
<em />
<em>V = π·r² = 3,14·(7,5)² = 3,14·56,25 = 176,625 ≈ 176,6 cm³</em>
Answer:
x = -5/2 , 5/2
Step-by-step explanation:
x^ -2 = 4/25
negative exponents means flip from numerator to denominator ( or vice versa)
(1/x) ^2 = 4/25
take the square root of each side (remember you get a positive and negative result)
sqrt(1/x) = sqrt(4/25)
1/x = + 2/5 1/x = -2/5
multiply each side by x
1 = + 2/5 x 1 = -2/5 x
multiply by 5/2 multiply by -5/2
5/2 = + 2/5 x * 5/2 -5/2 = -2/5 x *- 5/2
5/2 = + x -5/2 = x
x = 5/2 , -5/2
Answer:56
Step-by-step explanation:
.8 times 280 = 224 280-224=56
Answer:
4
Step-by-step explanation:
at x=3
since x=3 means x>= 1
use x+1 = 3+1=4
Perimeter of a rectangle = 6x + 8
Solution:
Given area of a rectangle = ![2x^2+7x+3](https://tex.z-dn.net/?f=2x%5E2%2B7x%2B3)
Let us first factor the given polynomial.
![2x^2+7x+3=2x^2+x+6x+3](https://tex.z-dn.net/?f=2x%5E2%2B7x%2B3%3D2x%5E2%2Bx%2B6x%2B3)
![=(2x^2+x)+(6x+3)](https://tex.z-dn.net/?f=%3D%282x%5E2%2Bx%29%2B%286x%2B3%29)
Taking out common terms in the above expression
Taking out common term
in the above expression
![=(2x+1)(x+3)](https://tex.z-dn.net/?f=%3D%282x%2B1%29%28x%2B3%29)
![2x^2+7x+3=(2x+1)(x+3)](https://tex.z-dn.net/?f=2x%5E2%2B7x%2B3%3D%282x%2B1%29%28x%2B3%29)
Area of a rectangle = l × b
Therefore,
and ![b=x+3](https://tex.z-dn.net/?f=b%3Dx%2B3)
Perimeter of a rectangle = 2(l + b)
![=2[(2x+1)+(x+3)]](https://tex.z-dn.net/?f=%3D2%5B%282x%2B1%29%2B%28x%2B3%29%5D)
![=2(2x+1+x+3)](https://tex.z-dn.net/?f=%3D2%282x%2B1%2Bx%2B3%29)
![=2(3x+4)](https://tex.z-dn.net/?f=%3D2%283x%2B4%29)
![=6x+8](https://tex.z-dn.net/?f=%3D6x%2B8)
The answer is same if you take <em>l</em> = x + 3 and <em>b</em> = 2x + 1.
Hence, perimeter of a rectangle = 6x + 8.