27 hours in the maximum hours
So in this case, we have to replace the known value.
y=3
y=-2x+3
3=-2x+3
Then we leave our unknown value alone.

= x
In this case, our x value would be 0.
We check it...
3=-2(0)+3
3=0+3
3=3
So y=3 x=0
For the second one we have...
y=3x+2
y=-3x-4
For this we substitute the y in any of the equation...
3x+2=-3x-4
We move the unknown values to one side and the ones without unlown values to the other side...
3x+3x=-4-2
Then we solve
6x=-6
Then we leave the unknown value alone.
x=

Then solve for x.
x= -1
Then for our y value we return to one of the original equations and substitute the x value.
y=3x+2
y=3(-1)+2
y=-3+2
y=-1
y=-3x-4
y=-3(-1)-4
y=3-4
y=-1
So in this case we got that x= -1 and y= -1
Answer:
D
Step-by-step explanation:
Answer:Three times the sum of x and seven plus ten
Step-by-step explanation:
You're going to have to work out the z-scores of both values in each option and see if it makes sense.
n = m + sz
The mean is 20 and the standard deviation is 3.
So let's find try the z-scores of the outer range values and determine their probabilities:
from 14-20:
n = m + sz
20 = 20 + 3z and 14 = 20 + 3z
0 = 3z and -6 = 3z
z = 0 and z = -2
So now using a z-score table, such as the one below, find the probabilities.
z = 0 is easy, it's 0.5
z = -2 is 0.02275
Subtract the smaller from the larger to get the probability of getting in the range:
0.5 - 0.02275 = 0.47725 (so times 1000, you get 477.25, which is not about 340, so this option is wrong)
---
Now trying option 2, from 17-29:
n = m + sz
29 = 20 + 3z and 17 = 20 + 3z
9 = 3z and -3 = 3z
z = 3 and z = -1
0.99865 - 0.158655 = 0.839995 (not 680, so not the answer)
---
Now trying option 3, from 20-23:
n = m + sz
23 = 20 + 3z and 20 = 20 + 3z
3 = 3z and 0 = 3z
z = 1 and z = 0
0.841345 - 0.5 = 0.341345 (close to 340, so is your answer)