All categories

2 years ago

-5y + 3x = 3 -8y + 9x = -12 solve for x and y

Mathematics

1 answer:

zzz [600]2 years ago

7 0

Answer:

x = -4 , y = -3

Step-by-step explanation:

Solve the following system:

{3 x - 5 y = 3 | (equation 1)

9 x - 8 y = -12 | (equation 2)

Swap equation 1 with equation 2:

{9 x - 8 y = -12 | (equation 1)

3 x - 5 y = 3 | (equation 2)

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

{9 x - 8 y = -12 | (equation 1)

0 x - (7 y)/3 = 7 | (equation 2)

Multiply equation 2 by 3/7:

{9 x - 8 y = -12 | (equation 1)

0 x - y = 3 | (equation 2)

Multiply equation 2 by -1:

{9 x - 8 y = -12 | (equation 1)

0 x+y = -3 | (equation 2)

Add 8 × (equation 2) to equation 1:

{9 x+0 y = -36 | (equation 1)

0 x+y = -3 | (equation 2)

Divide equation 1 by 9:

{x+0 y = -4 | (equation 1)

0 x+y = -3 | (equation 2)

Collect results:

Answer: {x = -4 , y = -3

You might be interested in

A juice drink filling machine, when in perfect adjustment, fills the bottles with 12 ounces of drink on an average. Any overfill

ozzi

Answer:

d. The average is equal to 12 ounces.

Step-by-step explanation:

In this problem, the drink filling machine must be perfectly calibrated at 12 ounces since it needs to be shut down in cases of overfilling (mean > 12 ounces) and underfilling (mean < 12 ounces). Therefore, the correct approach would be to test if the mean is 12 ounces and the correct set of hypothesis would be:

$H_0:\mu=12\\H_a:\mu\neq 12$

The correct alternative is d. The average is equal to 12 ounces.

5 0

2 years ago

A book costs d dollars.

bazaltina [42]

Answer:

The total amount paid by Jill = $ (3 d)

Step-by-step explanation:

Here, the cost of 1 book = $ d

Now, the number of books purchased by Jill = 3

So, the total cost of 3 books = 3 x ( Cost of 1 book)

= 3 x ($d) = 3 d

So, if Jill purchased 3 books, the total amount paid by her = $ (3 d)

3 0

2 years ago

In an anonymous survey 34 students reported the hours they studied for a statistics final exam. The histogram below shows the re

Darina [25.2K]

Answer:

Step-by-step explanation:

we have to use a mean to describe the center

4 0

2 years ago

If a certain number is increased by 5 one half of the result is three-fifths of the excess of 61 over the number find the number

PSYCHO15rus [73]

Answer:

= 391/11

Let say number = N

a certain number is increased by 5

= N + 5

,one-half of the result

= (N + 5)/2

Three -fifths of the excess of 61 over the number.

= (3/5)(61 - N)

Equating both

(N + 5)/2 = (3/5)(61 - N)

multiplying by 10 both sides

=> 5(N + 5) = 6(61 - N)

=> 5N + 25 = 366 - 6N

=> 11N = 391

=> N = 391/11

Step-by-step explanation:

8 0

2 years ago

The typical college freshman spends an average of μ=150 minutes per day, with a standard deviation of σ=50 minutes, on social me

Rashid [163]

Answer: The proportion of students spending at least 2 hours on social media equals 0.7257 .

Step-by-step explanation:

Given : The typical college freshman spends an average of μ=150 minutes per day, with a standard deviation of σ=50 minutes, on social media.

The distribution of time on social media is known to be Normal.

Let x be the number of minutes spent on social media.

Then, the probability that students spending at least 2 hours (2 hours = 120 minutes as 1 hour = 60 minutes) on social media would be:

$P(x\geq120)=1-P(x$

Hence, the proportion of students spending at least 2 hours on social media equals 0.7257 .

4 0

2 years ago