Answer:
x=-2, y=-6
Step-by-step explanation:
Simple substitution.
Since y is isolated in one of the equations already, you can plug it into the second equation.
x - 2(3x) = 10
x - 6x = 10
-5x = 10
x = -2
Sub. x = -2 into 3x = y:
3(-2) = y
y = -6
Answer:
2√2
Step-by-step explanation:
We can find the relationship of interest by solving the given equation for A, the mean distance.
<h3>Solve for A</h3>

<h3>Substitute values</h3>
The mean distance of planet X is found in terms of its period to be ...

The mean distance of planet Y can be found using the given relation ...

The mean distance of planet Y is increased from that of planet X by the factor ...
2√2
Answer:
X= -4
Step-by-step explanation:
^ you have to isolate the radical than raise each side to the power of its index which gets you
x= -4
Answer:
x=-4
Step-by-step explanation:
46 = -7x + 18
subtract 18 from each side to get:
28 = -7x
divide each side by -7 to get:
x = -4
Answer:
A score of 150.25 is necessary to reach the 75th percentile.
Step-by-step explanation:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
A set of test scores is normally distributed with a mean of 130 and a standard deviation of 30.
This means that 
What score is necessary to reach the 75th percentile?
This is X when Z has a pvalue of 0.75, so X when Z = 0.675.




A score of 150.25 is necessary to reach the 75th percentile.