4х - 16 = 6 * (3 + х)
4х - 16 = 18 + 6х
4х - 6х = 18 + 16
- 2х = 34
х = 34 : (- 2)
х = - 17
-------------------------------------------
4 * (- 17) - 16 = 6 * (3 + (- 17))
- 68 - 16 = 6 * (- 14)
- 84 = - 84
The domain { x | x = -5 , -3 , 1 , 2 , 6}
Answer:
The constant charge for each minute used is $50
Step-by-step explanation:
In order to solve this problem we will need to set two variables up. In this case:
F = constant Fee
R = rate per minute used
So the cost for the month of January is calculated like this:
F+300R=68
and the cost for February is calculated like this:
F+275R=66.5
So no we have a system of equations we can solve simultaneously. This can be solved by using different methods, elimination, substitution, graphically or by using matrices. I will solve this by substitution.
So let's solve the first equation for R:
![R=\frac{68-F}{300}](https://tex.z-dn.net/?f=R%3D%5Cfrac%7B68-F%7D%7B300%7D)
and let's substitute this first equation into the second equation:
![F+275(\frac{68-F}{300})=66.5](https://tex.z-dn.net/?f=F%2B275%28%5Cfrac%7B68-F%7D%7B300%7D%29%3D66.5)
and now we can solve this for F:
![F+11(\frac{68-F}{12})=66.5](https://tex.z-dn.net/?f=F%2B11%28%5Cfrac%7B68-F%7D%7B12%7D%29%3D66.5)
We can multiply both sides by 12 so we get:
12F+11(68-F)=798
12F+748-11F=798
F= $50
Answer:
At that moment dB/dt=0
Step-by-step explanation:
The area of a triangle is given by
A=bh/2
A=area, b=base, h=height
If we differentiate over time:
(product differentiation)
we have that:
![\frac{dH}{dt}=2.5 cm/m](https://tex.z-dn.net/?f=%5Cfrac%7BdH%7D%7Bdt%7D%3D2.5%20cm%2Fm)
![\frac{dA}{dt}=1.5 sqcm/m](https://tex.z-dn.net/?f=%5Cfrac%7BdA%7D%7Bdt%7D%3D1.5%20sqcm%2Fm)
When H=8 and A=84 then B is equal to
![84=\frac{8B}{2}](https://tex.z-dn.net/?f=84%3D%5Cfrac%7B8B%7D%7B2%7D)
![B=21](https://tex.z-dn.net/?f=B%3D21)
Therefore
![84 =\frac{dB}{dt}\frac{8}{2} +8*\frac{21}{2}](https://tex.z-dn.net/?f=84%20%3D%5Cfrac%7BdB%7D%7Bdt%7D%5Cfrac%7B8%7D%7B2%7D%20%20%2B8%2A%5Cfrac%7B21%7D%7B2%7D)
![\frac{dB}{dt}=0](https://tex.z-dn.net/?f=%5Cfrac%7BdB%7D%7Bdt%7D%3D0)