Answer:
A=-2; B=-1
Step-by-step explanation:
3a - 2b + 4 =0
2a -5b -1 = 0
Let's multiple the top equation by 2, and the bottom by -3, and then use addition.
[3a - 2b + 4 =0]*2
[2a -5b -1 = 0]*(-3)
6a-4b+8=0
-6a+15b+3=0
Now add the two equations together:
11b + 11 = 0
Subtract 11 from both sides
11b = -11
Divide both sides by 11
b=-1
Substitute in the first equation:
3a - 2(-1) + 4 = 0
Simplify to get 3a+6 = 0
Subtract 6 from both sides to get 3a = -6
Divide both sides by 3 to get a=-2
Answer:
Adults = x
Students = y = x + 40. 40 more student than adult
Adult = $8, Student = $6
Total for Adults = 8*x = 8x
Total for students = 6*y = 6y
Total = $1920
8x + 6y = 1920
Hence system of equations are:
y = x + 40
8x + 6y = 1920
First, distribute the 7:
7w + 14 + 0.5w = 5
Combine like terms:
7.5w + 14 = 5
7.5w = -9
Divide both sides by 7.5 to solve for w:
w = -9/7.5 = -1.2
The answer is -1.2
17 lbs and 4 oz. Because it is just doubling.
Answer:
b. 2.333
Step-by-step explanation:
Test if the mean transaction time exceeds 60 seconds.
At the null hypothesis, we test if the mean transaction time is of 60 seconds, that is:
At the alternate hypothesis, we test if it exceeds, that is:
The test statistic is:
In which X is the sample mean, 
is the value tested at the null hypothesis, s is the standard deviation of the sample and n is the size of the sample.
60 is tested at the null hypothesis:
This means that 
A sample of 16 ATM transactions shows a mean transaction time of 67 seconds with a standard deviation of 12 seconds.
This means that 
Value of the test statistic:
Thus, the correct answer is given by option b.
