3d + 8 = 2d - 7 equals d = -15.
First, subtract 2d from both sides. Your problem should look like: 3d + 8 - 2d = -7.
Second, simplify 3d + 8 - 2d to get d + 8. Your problem should look like: d + 8 = -7.
Third, subtract 8 from both sides. Your problem should look like: d = -7 - 8.
Fourth, simplify -7 - 8 to get -15. Your problem should look like: d = -15, which is your answer.
Hopefully this helps, I'm not exactly sure what you meant by "is equations," but this is how you solve the problem.
40x+30x=315
70x=315
315/70=
4.5 hours
12:00 noon + 4.5 hours = 4:30 pm
Turning a car on and off, turning the oven on and off
Answer:
The 98% confidence interval would be given by (55.639;62.361)
Step-by-step explanation:
Information given
represent the sample mean
represent the sample deviation
represent the sample size
Solution to the problem
The confidence interval for the mean is given by the following formula:
(1)
The degrees of freedom are given by:
The Confidence is 0.98 or 98%, the significance would be 
and 
,and the critical value would be 
And replacing we got:
The 98% confidence interval would be given by (55.639;62.361)
Answer:
Yes, because the population distribution is normally distributed, and we have a random sample.
Step-by-step explanation:
If the population is skewed, then the sample mean won't be normal for when N is small.
If the population is normal, then the distribution of sample mean looks normal even if N = 2.
If the population is skewed, then the distribution of sample mean looks more and more normal when N gets larger.
Since we have use 33% of the student, then N is large enough to conclude that the student are bad at guessing
