4X – 3 =2X+7 ....................................

What is the product?

makkiz [27]

Step-by-step explanation:

(4s + 2) × (5s² + 10s +3)

we know immediately the first and the last term of the result, because there is only one operation to build them :

20s³ and 6.

so, the first answer option is already eliminated.

let's multiply

4s×5s² + 4s×10s + 4×3s + 10s² + 20s + 6

20s³ + 40s² + 12s + 10s² + 20s + 6

20s³ + 50s² + 32s + 6

so, the last answer option is correct.

4 0

2 years ago

I NEED UR HELPFNGKFNKFJFF

alisha [4.7K]

For Q3, you can subsitute x = 2 and y = 5 into the systems

-5(2) + 5 = -5

so it's a solution for the first system

-4(2)+2(5) = 2

it's also a solution for the second system

8 0

2 years ago

A rectangular garden has a perimeter of 36 yards and a width of 8 yards.

xeze [42]

Answer:

80 square yards

Step-by-step explanation:

We know we have a width of 8 yards and a perimeter of 36.

how I figured it out was:

36=(8*2) * (x*2)

8*2=16

36-16=10

So now we know the length and width.

area of a rectangle is lw (length * width)

10*8=80.

8 0

3 years ago

A government report gives a 99% confidence interval for the proportion of welfare recipients who have been receiving welfare ben

juin [17]

Answer:

The estimation for the proportion for this case is $\hat p = 0.21$

And we know that the 99% confidence interval is given by:

$0.21 \pm 0.045$

So then the margin of error at 99% of confidence is 0.045, and the margin of error is given by this formula:

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

If we decrease the confidence level this margin of error can't be higher than 0.045 so then the correct answer for this case would be:

d. 21% ± 4.8%

Because if the z value decrease from 2.58 to 1.96 not makes sense that the margin of error increase from 0.045(4.5%) to 0.048(4.8%)

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

Solution to the problem

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{\hat p(1-\hat p)}{n}})$

The confidence interval would be given by this formula

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

For the 95% confidence interval the value of $\alpha=1-0.95=0.05$ and $\alpha/2=0.025$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=1.96$

For the 99% confidence interval the value of $\alpha=1-0.99=0.01$ and $\alpha/2=0.005$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=2.58$

The estimation for the proportion for this case is $\hat p = 0.21$

And we know that the 99% confidence interval is given by:

$0.21 \pm 0.045$

So then the margin of error at 99% of confidence is 0.045, and the margin of error is given by this formula:

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

If we decrease the confidence level this margin of error can't be higher than 0.045 so then the correct answer for this case would be:

d. 21% ± 4.8%

Because if the z value decrease from 2.58 to 1.96 not makes sense that the margin of error increase from 0.045(4.5%) to 0.048(4.8%)

5 0

3 years ago

Melania has two jobs. During the day she works as an office clerk, and in the evening she works as a cashier. her office job pay

bulgar [2K]

Lets x = # of hours Melania works at office clerk
and y = # of hours Melania works as a cashier

x + y = 38 so x = 38 - y
13x + 9.25y = 434

substitute x = 38 - y into 13x + 9.25y = 434

13x + 9.25y = 434
13(38 - y) + 9.25y = 434
494 - 13y + 9.25y = 434
-3.75y = -60
y = 16
x = 38 - y so x = 38 - 16 = 22

answer
Melania works at office clerk = 22 hours
Melania works as a cashier = 16 hours

7 0

3 years ago

4X – 3 =2X+7....................................​

4X – 3 =2X+7....................................