Answer: I don’t think u gave enough info
Step-by-step explanation:
Answer:
Equivalent systems of equations review
Step-by-step explanation:
We're given two systems of equations and asked if they're equivalent.
x + 4y = 8 (1)
4x + y = 2 (2)
Interestingly, if we sum the equations in System A, we get:
Replacing the first equation in System A with this new equation, we get a system that's equivalent to System A:
This is System B, which means that System A is equivalent to System B.
Simplifying
8x + -10 = 62
Reorder the terms:
-10 + 8x = 62
Solving
-10 + 8x = 62
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '10' to each side of the equation.
-10 + 10 + 8x = 62 + 10
Combine like terms: -10 + 10 = 0
0 + 8x = 62 + 10
8x = 62 + 10
Combine like terms: 62 + 10 = 72
8x = 72
Divide each side by '8'.
x = 9
Simplifying
x = 9
Given the point:
(x, y) ==> (9, 2)
Let's find the new point of the image after a rotation of 90 degrees counterclockwise about the origin.
To find the image of the point after a rotation of 90 degrees counterclockwise, apply the rules of rotation.
After a rotation of 90 degrees counterclockwise, the point (x, y) changes to (-y, x)
Thus, we have the point after the rotation:
(x, y) ==> (-y, x)
(9, 2) ==> (-2, 9)
Therefore, the image of the points after a rotation of 90 degrees counterclockwise is:
(-2, 9)
ANSWER:
(-2, 9)
The percentage of young adults send between 128 and 158 text messages per day is; 34%
<h3>How to find the percentage from z-score?</h3>
The distribution is approximately Normal, with a mean of 128 messages and a standard deviation of 30 messages.
We are given;
Sample mean; x' = 158
Population mean; μ = 128
standard deviation; σ = 30
We want to find the area under the curve from x = 248 to x = 158.
where x is the number of text messages sent per day.
To find P(158 < x < 248), we will convert the score x = 158 to its corresponding z score as;
z = (x - μ)/σ
z = (158 - 128)/30
z = 30/30
z = 1
This tells us that the score x = 158 is exactly one standard deviation above the mean μ = 128.
From online p-value from z-score calculator, we have;
P-value = 0.34134 = 34%
Approximately 34% of the the population sends between 128 and 158 text messages per day.
Read more about p-value from z-score at; brainly.com/question/25638875
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