Answer:
-7
Step-by-step explanation:
Let the number be x
So we get equation : 3x + 8 = -13
Thus, 3x = -13-8 = -21
So, x = (-21)/3
Hence the required number is -7
Answer:
x= 6
Step-by-step explanation:
![\frac{1}{3}x^{2}-5=7\\](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B3%7Dx%5E%7B2%7D-5%3D7%5C%5C)
Add 5 to both sides
![\frac{1}{3}x^{2}-5+5=7+5\\\\\frac{1}{3}x^{2}=12\\](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B3%7Dx%5E%7B2%7D-5%2B5%3D7%2B5%5C%5C%5C%5C%5Cfrac%7B1%7D%7B3%7Dx%5E%7B2%7D%3D12%5C%5C)
Multiply both sides by 3
![3*\frac{1}{3}x^{2}=12*3\\\\x^{2}=36\\](https://tex.z-dn.net/?f=3%2A%5Cfrac%7B1%7D%7B3%7Dx%5E%7B2%7D%3D12%2A3%5C%5C%5C%5Cx%5E%7B2%7D%3D36%5C%5C)
x² = 6*6
Take square root,
√x² =√6*6
x = 6
Answer:
314.2ft^2
Step-by-step explanation:
Given data
Diameter= 20ft
Radius r= 20/2= 10ft
The expression for the area is
A= πr^2
A= 3.142*10^2
A= 3.142*100
A= 314.2ft^2
Hence the area is 314.2ft^2