0=0
Step-by-step explanation:
4(×+3)=4x+12
4x+12=4x+12
Subtract 12 from both sides of the equation
4x+12-12=4x+12-12
simplify
4x=4x
Subtract 4x from both sides of the equation
4x-4x= 4x-4x
Simplify and combine like terms
0=0
<h3>
<u>Explanation</u></h3>
- Convert the equation into slope-intercept form.

where m = slope and b = y-intercept.
What we have to do is to make the y-term as the subject of equation.


From y = mx+b, the slope is 3.
<h3>
<u>Answer</u></h3>

The choices are <span><span> A. r= 200 over w; r = 40 B. r = 200 over w; C. r = 1000
C. r = 2w; r = 10 D. r = 2w; r = 2.5. T</span>he situation</span> implies that the number of roses is inversely proportional to the number of weeds. In this case, the answer is either a or b. Given 5 weeds,the one that fits is A. <span>A. r= 200 over w; r = 40. </span>
The question is incomplete! Complete question along with answer and step by step explanation is provided below.
Question:
The lifetime (in hours) of a 60-watt light bulb is a random variable that has a Normal distribution with σ = 30 hours. A random sample of 25 bulbs put on test produced a sample mean lifetime of = 1038 hours.
If in the study of the lifetime of 60-watt light bulbs it was desired to have a margin of error no larger than 6 hours with 99% confidence, how many randomly selected 60-watt light bulbs should be tested to achieve this result?
Given Information:
standard deviation = σ = 30 hours
confidence level = 99%
Margin of error = 6 hours
Required Information:
sample size = n = ?
Answer:
sample size = n ≈ 165
Step-by-step explanation:
We know that margin of error is given by
Margin of error = z*(σ/√n)
Where z is the corresponding confidence level score, σ is the standard deviation and n is the sample size
√n = z*σ/Margin of error
squaring both sides
n = (z*σ/Margin of error)²
For 99% confidence level the z-score is 2.576
n = (2.576*30/6)²
n = 164.73
since number of bulbs cannot be in fraction so rounding off yields
n ≈ 165
Therefore, a sample size of 165 bulbs is needed to ensure a margin of error not greater than 6 hours.