All categories

3 years ago

Which is a solution to the equation 10-5y = 20? y=2 y=4 y = 6 y = 10

Mathematics

1 answer:

iVinArrow [24]3 years ago

8 0

Answer:

The correction answer is y = - 2

Step-by-step explanation:

10-5y=20

-5y=10

y=10/-5

y=-2

You might be interested in

The length of a rectangle is 6 centimeters and its area is (6x + 18)square centimeters. Write an expression for the width.

Alecsey [184]

Area=legnth times width
legnth=6
area=6x+18
subsitute
6x+18=6 times width

undistribute 6 from each term on left side
6(x+3)=6 times width
divide both sides by 6
x+3=width

5 0

3 years ago

Suppose you wanted to estimate the time in minutes the average person spends on e-mail a day. It’s estimated that the standard d

ZanzabumX [31]

Answer:

We need a sample size of at least 1698.

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1-0.99}{2} = 0.005$

Now, we have to find z in the Ztable as such z has a pvalue of $1-\alpha$ .

So it is z with a pvalue of $1-0.005 = 0.995$ , so $z = 2.575$

Now, find the margin of error M as such

$M = z*\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

You want the margin of error to be only one minute. What sample size do you need if the confidence level is 99%?

This is at least n when $M = 1, \sigma = 16$ . So

$M = z*\frac{\sigma}{\sqrt{n}}$

$1 = 2.575*\frac{16}{\sqrt{n}}$

$\sqrt{n} = 2.575*16$

$(\sqrt{n})^{2} = (2.575*16)^{2}$

$n = 1697.4$

Rouding up

We need a sample size of at least 1698.

3 0

3 years ago

doug has 45 coins worth $9.00. The coins are all quarters or dimes. How many of each type of coin dose doug have?

Kaylis [27]

Doug have 30 quarters and 15 dimes.

Step-by-step explanation:

Given,

Number of coins = 45

Worth of coins = $9.00 = 9.00*100 = 900 cents

Each quarter = 25 cents

Each dime = 10 cents

Let,

x be the number of quarters

y be the number of dimes

According to given statement;

x+y=45 Eqn 1

25x+10y=900 Eqn 2

Multiplying Eqn 1 by 10

$10(x+y=45)\\10x+10y=450\ \ \ Eqn\ 3$

Subtracting Eqn 3 from Eqn 2

$(25x+10y)-(10x+10y)=900-450\\25x+10y-10x-10y=450\\15x=450$

Dividing both sides by 15

$\frac{15x}{15}=\frac{450}{15}\\x=30$

Putting x=30 in Eqn 1

$30+y=45\\y=45-30\\y=15$

Doug have 30 quarters and 15 dimes.

Keywords: linear equation, elimination method

Learn more about elimination method at:

#LearnwithBrainly

5 0

3 years ago

Lisa wants to buy material for her dress. If she buys 7metres, she is 1 dollar short. If she buys 5metres, 5 dollars is left ove

Ede4ka [16]

Answer:

She has 15 dollar.

Explanation

If every meter costs 2 dollars, then 5 meter would cost 10 dollars and 7 meter would cost 14 dollar. Now we take a number when subtracted from 10, we get 5 dollar and when the same number subtracted from 14 we get 1 dollar left. Now if we take 15 dollar, you'll see that when you subtract 10 from it you get 5 dollar and when you subtract 14 from it you get 1 dollar. Therefore 15 satisfies the given condition in the question.

$15 - $10 = $5

$15 - $14 = $1

4 0

3 years ago

Identify the slope of the line 3x-5y=20

liubo4ka [24]

Y=3/5x-20
Hope this helps

8 0

3 years ago

Read 2 more answers