Answer:
A third group that does not use a cell phone before bedtime
Step-by-step explanation:
Both groups have the use of a cellphone before bedtime, and the amount used would affect their time to fall asleep, but another group is needed that doesn't use a cellphone to calculate the effect of it not being used and seeing the results.
Substitution method is used to solve the linear system of equations for one or more variables.
Consider the first equation y = 3x + 3 -----(1)
In equation (1) plug in y=x-1, we get
x -1 = 3x + 3
Add -3x on both side , we get
x-3x -1 = 3x-3x +3
-2x-1=0 + 3
Now add +1 on both sides, we get
-2x-1+1= 3+1
-2x + 0 =4
Now divide both side by -2
-2x/-2= 4/-2
X= -2
Now put x=-2 in the the second equation,
y=x-1
y=(-2)-1
y=-3
Solution(-2,-3)
The probability of rolling factors of 4 are 4/1 or 2/1
Step-by-step explanation: The place value chart can help us write a number in expanded notation. When we put 2,930,365 into the place value chart, we can recognize that our number is equal to 2 millions + 9 hundred thousands + 3 ten thousands + 0 thousands + 3 hundreds + 6 tens + 5 units.
The place value chart is attached in the image provided.