Answer:
hours
Step-by-step explanation:
Let x be the time ( in hours ) you feel good and y be the time ( in hours ) that you get tired.
As per given , we have
x+y= 8
Since : 
So , we have
20x+12y=122
According to the given question , we have the following system of equations ,

Multiply 12 on both sides of equation (1) , we get

Eliminate equation (3) from (2) , we get

Hence, you felt
hours good.
Answer:
The standard deviation is 2.6832815729997
Step-by-step explanation:
SD^2=(12-12)^2+...+(14-12)^2/10
SD^2=72/10
SD^2=7.2
SD=squeare root of 7.2
SD=2.6832815729997
The first equation is $3 times 9 = $27 the next equation iis $1 times 2 = $1
So you do 9 transactions over $100 and 2 transactions of $100 or lower.
1) Since the larger number is a negative, you’re going to get a negative solution for number one. An easy way to do the math is to ignore the negative sign in (-116) For a moment. And subtract 56 from it.
116 - 56 = 60. Don’t forget to place the negative sign we pushed to this side before the solution. The answer is -60.
2) We do the same thing we did in number one, but with new numbers. The answer in total is -178.
3. As stated, we do the same thing we did in number one. Just because there’s a decimal doesn’t change much. And your answer would be -1.1
345= 3 hundreds, 4 tens, and 5 ones
391= 3 hundreds, 9 tens, and 1 one
You can use the model I attached to help u see it better.
Hope this helps!