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3 years ago

Solve the system by elimination. Show your work. 3) -x - 18 y = -3 and 7x - 9 y = 21

Mathematics

1 answer:

makvit [3.9K]3 years ago

6 0

This is what i got not sure if it’s right

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Cindy earns $10.50 per hour working at a restaurant. On Friday, she spent 1 3/4 hours cleaning, 2 1/3 hours doing paperwork, and

AnnyKZ [126]

$61.25

All you have to do is add all the fractions and multiply it by 10.50

7 0

3 years ago

What is the coordinate j(2,-5) after a reflection in the line y=x?

kenny6666 [7]

Answer:

(- 5, 2 )

Step-by-step explanation:

Under a reflection in the line y = x

a point (x, y ) → (y, x ), thus

(2, - 5 ) → (- 5, 2 )

7 0

3 years ago

It costs $68 for 16 square feet of flooring. How much does it cost for 12 square feet of flooring?

belka [17]

We know that it costs $68 for 16 square feet of flooring. To find out how much it costs for 12, we first have to find out how much it costs for 1 square foot.
To find that, we would do $68 divided by 16, which is 4.25.
That means 1 square foot costs $4.25.
Then, we would multiply $4.25 by 12 to find how much 12 square feet costs.
$4.25 times 12 is 51.

So, it would cost $51 to have 12 square feet of flooring.

5 0

4 years ago

Points N and R both lie on circle O. Line segment RQ is tangent to the circle at point R.

4vir4ik [10]

Answer:

15.0

Step-by-step explanation:

Let's start by looking at triangle ORQ. Since RQ is tangent to the circle, we know that angle ∠ORQ is 90°. Then, since OR is equivalent to the radius of 5, RQ is 5√3, and side OQ is clearly larger than RQ, we can identify this as a 90-60-30 degree triangle. This makes side OQ have a length of 10, and angle ∠QOR, opposite of the second largest side, has the second largest angle of 60°, leaving ∠OQR with an angle of 30°.

The formula for the chord length is 2r*sin(c/2), with c being the angle between the two points on the circle (in this case, ∠QOR=∠NOR).. Our radius is 5, so the length of chord NR is 2*5*sin(60/2)=5, making our answer 5(ON)+5(OR)+5(RN)

4 0

3 years ago

Read 2 more answers

A videotape store has an average weekly gross of $1,158 with a standard deviation of $120. Let x be the store's gross during a r

statuscvo [17]

Answer:

The number of standard deviations from $1,158 to $1,360 is 1.68.

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

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.

In this problem, we have that:

$\mu = 1158, \sigma = 120$

The number of standard deviations from $1,158 to $1,360 is:

This is Z when X = 1360. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{1360 - 1158}{120}$

$Z = 1.68$

The number of standard deviations from $1,158 to $1,360 is 1.68.

3 0

3 years ago