9514 1404 393
Answer:
(3, 1)
Step-by-step explanation:
We assume you want the solution to the system ...
The second equation gives a nice expression for x, so we can use that in the first equation.
2(y+2) -3y = 3 . . . . substitute for x in the first equation
2y +4 -3y = 3 . . . . . eliminate parentheses
-y = -1 . . . . . . . . . . . collect terms, subtract 4
y = 1 . . . . . . . . . . . . multiply by -1
x = 1 +2 = 3 . . . . . . substitute for y in the second equation
The solution is (x, y) = (3, 1).
The answer is . (one [point] 4)
((Yes, its correct, checked and took an exam on it))
answer
z = 100
opposite angles
when inscribed in a circle, the opposite angles of a quadrilateral add up to 180
so z + 80 = 180 and y + 120 = 180
solve for z
z + 80 = 180
z = 180 - 80
z = 100
7 2/6 + 8 5/6
= (7 x 6 + 2)/6 + (8 x 6 + 5)/6
= (42 + 2)/6 + (48 + 5)/6
= 44/6 + 53/6
= (44 + 53)/6
= 97/6
= 16 1/6
121 is big enough to assume normality and not worry about the t distribution. By the 68-95-99.7 rule a 95% confidence interval includes plus or minus two standard deviations. So 95% of the cars will be in the mph range
The question is a bit vague, but it seems we're being asked for the 95% confidence interval on the average of 121 cars. The 121 is a hint of course.
The standard deviation of the average is in general the standard deviation of the individual samples divided by the square root of n:
So repeating our experiment of taking the average 121 cars over and over, we expect 95% of the averages to be in the mph range
That's probably the answer they're looking for.
