Answer:
not sure
Step-by-step explanation:
us a calculator
Answer:
x = -4
Step-by-step explanation:
2x+4(2x+7)=3(2x+4)
Distribute
2x+8x + 28 = 6x +12
Combine like terms
10x +28 = 6x +12
Subtract 6x from each side
10-6x+28 = 6x +12 -6x
4x +28 = 12
Subtract 28 from each side
4x+28-28 = 12-28
4x = -16
Divide each side by 4
4x/4 = -16/4
x = -4
Answer:
Alan: 200 m/min
Brian: 150 m/min
Step-by-step explanation:
Given : Two cyclists, Alan and Brian, are racing around oval track of length 450m on the same direction simultaneously from the same point. Alan races around the track in 45 seconds before Brian does and overtakes him every 9 minutes.
To find : What are their rates, in meters per minute?
Solution :
Let n represent the number of laps that Alan completes in 9 minutes.
Then n-1 is the number of laps Brian completes.
45 seconds = 3/4 minutes.
The difference in their lap times in minutes per lap is

Solving the equation we get,








Neglecting n=-3
So, n=4
Then Alan's speed in m/min is



Brian completes 3 laps in that 9-minute time, so his rate is


Therefore, Alan: 200 m/min
Brian: 150 m/min
Answer: 0.8461
Step-by-step explanation:
Let p be the proportion of residents are against the increase of taxes to fund alternatives to drug addiction treatment.
As per given , we have p=0.40
A random sample is taken with size : n= 400
Expecting sample proportion : 
Now , the probability that more than 150 of the residents surveyed will be against increasing taxes if a random sample of 400 residents are surveyed will be :

![=P(z>\dfrac{0.375-0.40}{\sqrt{\dfrac{0.40(0.60)}{400}}})\ \ [\because\ z=\dfrac{\hat{p}-p}{\sqrt{\dfrac{p(1-p)}{n}}}]](https://tex.z-dn.net/?f=%3DP%28z%3E%5Cdfrac%7B0.375-0.40%7D%7B%5Csqrt%7B%5Cdfrac%7B0.40%280.60%29%7D%7B400%7D%7D%7D%29%5C%20%5C%20%5B%5Cbecause%5C%20z%3D%5Cdfrac%7B%5Chat%7Bp%7D-p%7D%7B%5Csqrt%7B%5Cdfrac%7Bp%281-p%29%7D%7Bn%7D%7D%7D%5D)

[By z-table]
Hence, the approximate probability that more than 150 of the residents surveyed will be against increasing taxes if a random sample of 400 residents are surveyed is 0.8461 .