All categories

3 years ago

Please help me out!

Mathematics

1 answer:

garik1379 [7]3 years ago

5 0

1. there are two methods to solve this system

I.substition

from the first relation we can deduct

2a-b=4

2a=4+b

a=(4+b)/2

now we substitute a in the second relation

(4+b)/2+b=5

we multiply by 2

4+b+2b=10

3b=6

b=6/3=2

a+2=5

a=3

II.reduction

2a-b=4

a+b=5

we can add the two relations together

2a+a-b+b=4+5

3a=9

a=3

3+b=5

b=2

You might be interested in

A car is traveling down a highway at a constant speed, described by the equation d=65t , where d represents the distance, in mil

notsponge [240]

Answer: 97.5m

Step-by-step explanation:

5 0

3 years ago

What is the constant of posprtainality in the equation y=0.41

KATRIN_1 [288]

Answer:

The constant of proportionality in the equation y=0.41 is 0.41

Step-by-step explanation:

5 0

3 years ago

The sale price S (in dollars) of an item is given by the formula S=L−rL, where L is the list price (in dollars) and r is the dis

ser-zykov [4K]

The sale price S (in dollars) of an item is given by the formula

S=L−rL , where L is the list price (in dollars) and r is the discount rate.

Since, S = L -rL

rL = L -S

r = $\frac{L-S}{L}$

r = $1-\frac{S}{L}$

Since, the listed price of the shirt is $30, we have to find the discount rate.

Therefore, r = $1-\frac{S}{30}$ is the discount rate.

7 0

3 years ago

Read 2 more answers

An amusement park would like to determine if they want to add in a new roller coaster. In order to decide whether or not they sh

Rzqust [24]

Using the z-distribution, it is found that the 90% confidence interval is given by: (0.6350, 0.6984).

<h3>What is a confidence interval of proportions?</h3>

A confidence interval of proportions is given by:

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which:

$\pi$ is the sample proportion.

z is the critical value.

n is the sample size.

In this problem, we have a 90% confidence level, hence $\alpha = 0.9$ , z is the value of Z that has a p-value of $\frac{1+0.9}{2} = 0.95$ , so the critical value is z = 1.645.

The sample size and the estimate are given by:

$n = 600, \pi = \frac{400}{600} = 0.6667$

Hence, the bounds of the interval are given by:

$\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.6667 - 1.645\sqrt{\frac{0.6667(0.3333)}{600}} = 0.6350$

$\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.6667 + 1.645\sqrt{\frac{0.6667(0.3333)}{600}} = 0.6984$

The 90% confidence interval is given by: (0.6350, 0.6984).

More can be learned about the z-distribution at brainly.com/question/25890103

#SPJ1

5 0

2 years ago

A chef is going to use a mixture of two brands of Italian dressing. The first brand contains 7% vinegar, and the second brand co

Lina20 [59]

Answer: There is 162 ml of first brand and 108 ml of second brand.

Step-by-step explanation:

Since we have given that

Percentage of vinegar that the first brand contains = 7%

Percentage of vinegar that the second brand contains = 12%

Percentage of vinegar in mixture = 9%

Total amount of dressing = 270 ml

We will use "Mixture and Allegation":

First brand Second brand

7% 12%

--------------------------------------------------------

12%-9% : 9%-7%

3% : 2%

So, ratio of first brand to second brand in a mixture is 3:2.

So, Amount of first brand she should use is given by

$\dfrac{3}{5}\times 270\\\\=162\ ml$

Amount of second brand she should use is given by

$\dfrac{2}{5}\times 270\\\\=108\ ml$

Hence, there is 162 ml of first brand and 108 ml of second brand.

4 0

3 years ago

Please help me out! ​

Please help me out!