All categories

3 years ago

Solve the system of linear equations using elimination. −7x + 3y = −6 −3x + 3y = 6

Mathematics

2 answers:

Marysya12 [62]3 years ago

8 0

Answer:

x = 3 , y = 5

Step-by-step explanation:

Solve the following system:

{3 y - 7 x = -6 | (equation 1)

3 y - 3 x = 6 | (equation 2)

Subtract 3/7 × (equation 1) from equation 2:

{-(7 x) + 3 y = -6 | (equation 1)

0 x+(12 y)/7 = 60/7 | (equation 2)

Multiply equation 2 by 7/12:

{-(7 x) + 3 y = -6 | (equation 1)

0 x+y = 5 | (equation 2)

Subtract 3 × (equation 2) from equation 1:

{-(7 x)+0 y = -21 | (equation 1)

0 x+y = 5 | (equation 2)

Divide equation 1 by -7:

{x+0 y = 3 | (equation 1)

0 x+y = 5 | (equation 2)

Collect results:

Answer: {x = 3 , y = 5

jolli1 [7]3 years ago

3 0

Answer:

(3, 5)

Step-by-step explanation:

−7x + 3y = −6

−3x + 3y = 6

Subtract the second equation from the first.

−4x = −12

x = 3

Then substitute. → −7x + 3y = −6 → −7(3) + 3y = −6

y = 5

You might be interested in

It takes 4 people 6 days to paint a wall. How many days would it take 12 people

Aleks04 [339]

Answer:

There are more than one way to do this:

Here's one way:

The least common multiple of 4 people and 3 people is 12 people.

12 people is 3 times as many people as 4 people, and

12 people is 4 times as many as 3 people.

Since 4 people take 6 days, 3 times as many people take only

one-third as long, or only 2 days. (since 2 is one-third of 6)

Since 3 people is only one-fourth as many people as 12, it will take

them 4 times as long as it would take 12 people, or 8 days. (since

4 times 2 is 8).

Step-by-step explanation:

subtract 8 from 12

4 days

6 0

3 years ago

(multiple choice) plz help me!!

harkovskaia [24]

$8 \sqrt{5} is \: the \: length$

Step-by-step explanation:

$( {16})^{2} = ( {x})^{2} - ( {8})^{2} \\ 256 = {x}^{2} - 64 \\ 256 + 64 = {x}^{2} \\ \sqrt{320} = \sqrt{ {x}^{2} } \\ 8 \sqrt{5} = x$

7 0

3 years ago

IQ scores are normally normally distributed with a mean of 100 and center deviation of 15 if one person is randomly selected wha

Arlecino [84]

Answer:

22.86% probability that the persons IQ is between 110 and 130

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:

$\mu = 100, \sigma = 15$

If one person is randomly selected what is the probability that the persons IQ is between 110 and 130

This is the pvalue of Z when X = 130 subtracted by the pvalue of Z when X = 110.

X = 130

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

$Z = \frac{130 - 100}{15}$

$Z = 2$

$Z = 2$ has a pvalue of 0.9772

X = 110

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

$Z = \frac{110 - 100}{15}$

$Z = 0.67$

$Z = 0.67$ has a pvalue of 0.7486

0.9772 - 0.7486 = 0.2286

22.86% probability that the persons IQ is between 110 and 130

6 0

3 years ago

Which expression is equivalent to (-3y - x) - (5y - 8x)?

Vinil7 [7]

Answer:

Step-by-step explanation:

plz mark brainliest

4 0

3 years ago

If a box of 100 pencils cost $4.75, what should you expect to pay for 225 pencils?

skad [1K]

Answer:

$ 10.69

Step-by-step explanation:

225 is 2.25 times the 100 pencils. ( 225/100) So all you have to do is multiply 2.25 the price ($4.75) and you get 10.6875, money can only go to the tenth place so you round it to $10.69

Hope this helped and pls mark as brainliest!

~Luna

6 0

3 years ago

Read 2 more answers