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3 years ago

Solve this system of equations using substitution:

Mathematics

1 answer:

yanalaym [24]3 years ago

4 0

I’m thinking your r in the first equation is actually an x.

X + 2(2x -4) =10

X +4x -8 =10

5x = 18

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Write the equation of a line with a y intercept of (5,0) that goes through the points (2,6) and (-1,12)

kodGreya [7K]

Answer:

it goes diagnoly

Step-by-step explanation:

because

7 0

3 years ago

PTC is a substance that has a strong bitter taste for some people and is tasteless for others. The ability to taste PTC is inher

lana66690 [7]

Answer:

a) $n=\frac{0.76(1-0.76)}{(\frac{0.01}{1.64})^2}=4905.83$

And rounded up we have that n=4906

b) For this case since we don't have prior info we need to use as estimatro for the proportion $\hat p =0.5$

$n=\frac{0.5(1-0.5)}{(\frac{0.01}{1.64})^2}=6724$

And rounded up we have that n=6724

Step-by-step explanation:

We need to remember that the confidence interval for the true proportion is given by :

$\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$

Part a

The estimated proportion for this case is $\hat p =0.76$

Our interval is at 90% of confidence, and the significance level is given by $\alpha=1-0.90=0.1$ and $\alpha/2 =0.05$ . The critical values for this case are:

$z_{\alpha/2}=-1.64, t_{1-\alpha/2}=1.64$

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

The margin of error desired is given $ME =\pm 0.01$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

Replacing we got:

$n=\frac{0.76(1-0.76)}{(\frac{0.01}{1.64})^2}=4905.83$

And rounded up we have that n=4906

Part b

For this case since we don't have prior info we need to use as estimatro for the proportion $\hat p =0.5$

$n=\frac{0.5(1-0.5)}{(\frac{0.01}{1.64})^2}=6724$

And rounded up we have that n=6724

3 0

3 years ago

On Tuesday Emily bought four posters,

hram777 [196]

Answer: 16 posters

Step-by-step explanation:

Monday - Had owned 16 posters

Tuesday - Bought 4 posters, adding up to 20

Wednesday - Half of the posters were destroyed, half of 20 is 10

Thursday - 10 posters remained.

8 0

3 years ago

Read 2 more answers

Easy question i will mark braineliest

Yuki888 [10]

Answer:

Step-by-step explanation:

$5(y - 3.8) = 4.7(y - 4)$

Distribute 5 through the parentheses

$5y - 19 = 4.7(y - 4)$

Distribute 4.7 through the parentheses

$5y - 19 = 4.7y - 18.8$

Move ' 4.7 y ' to L.H.S and change it's sign

$5y - 4.7y - 19 = - 18.8$

Move constant to R.H.S and change it's sign

$5y - 4.7y = - 18.8 + 19$

Collect like terms

$0.3y = - 18.8 + 19$

Calculate

$0.3y = 0.2$

Divide both sides of the equation by 0.3

$\frac{0.3y}{0.3} = \frac{0.2}{0.3}$

Calculate

$y = 0.67$

Hope this helps...

Best regards!!

3 0

3 years ago

Read 2 more answers

The discount on a new stereo was $180. This was a discount of 18%. What was the original selling price?

vladimir2022 [97]

Answer:

$212.40

Step-by-step explanation:

180+ (180* 18%)= Total Cost

180+ 32.40= Total Cost

212.40= Total Cost

8 0

3 years ago