Factor 7x3y4−7x2y5 completely.

liam is reading a 254-page book for school. He can read 40 pages in one hour. The equation for the number of pages he has left t

Serggg [28]

Actually, it is
pages left=total pages-pages read
pages read=(number of pages per hour) times (number of hours)
numbe rof pages per hour=40
x=number of hours
254=total pages
so
y=254-40x, not 4x

what is the question
if it is how many hours to read the book then
0=pages left
0=254-40x
add 40x to both sides
40x=254
divide by 40
x=6.35
6.35 days or aprox 7 days

equation is y=254-40x where y=pages left and x=number of hours read

5 0

3 years ago

Tom has been given 35 chores to complete today. This morning he finished 7 of them. How many chores does he now have left to do?

tamaranim1 [39]

He has 28 chores left to do. Just subtract.

7 0

3 years ago

Read 2 more answers

7. (0) + (-9) * (+8) =

ivolga24 [154]

Answer:

-72

Step-by-step explanation:

7 0

3 years ago

(1 point) The effectiveness of a new bug repellent is tested on 18 subjects for a 10 hour period. Based on the number and locati

jolli1 [7]

Answer:

z=1.59

If we compare the p value and the significance level given $\alpha=0.025$ we see that $p_v>\alpha$ so we can conclude that we fail to reject the null hypothesis, so we can conclude that the mean repellency of the new bug repellent is greater than 89% at 0.025 of signficance.

Step-by-step explanation:

1) Data given and notation

$\bar X=0.92$ represent the mean effectiveness of a new bug repellent for the sample

$\sigma=0.08$ represent the population standard deviation for the sample

$n=18$ sample size

$\mu_o =0.89$ represent the value that we want to test

$\alpha=0.025$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to determine if the mean repellency of the new bug repellent is greater than 89% or 0.89, the system of hypothesis would be:

Null hypothesis: $\mu \leq 0.89$

Alternative hypothesis: $\mu > 0.89$

We don't know the population deviation, and the sample size <30, so for this case is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$t=\frac{0.92-0.89}{\frac{0.08}{\sqrt{18}}}=1.59$

Calculate the P-value

First we need to calculate the degrees of freedom given by:

$df=n-1=18-1=17$

Since is a one-side upper test the p value would be:

$p_v =P(t_{17}>1.59)=0.065$

In Excel we can use the following formula to find the p value "=1-T.DIST(1.59;17;TRUE)"

Conclusion

If we compare the p value and the significance level given $\alpha=0.025$ we see that $p_v>\alpha$ so we can conclude that we fail to reject the null hypothesis, so we can conclude that the mean repellency of the new bug repellent is greater than 89% at 0.025 of signficance.

6 0

4 years ago

Choose the correct equation for the parabola based on the given information. Given: Focus:(2,8) Directrix: y = 4 a. 2(y-2)= (x-

Harman [31]

<h3>Answer: c. 8(y-6) = (x-2)^2</h3>

Explanation:

The directrix is horizontal, so the axis of symmetry is vertical. We'll have an x^2 term. The vertical distance from y = 4 to y = 8 is 4 units. Cut this in half to get 2, which is the focal distance p = 2.

The point (2,4) is directly below (2,8), and the point is on the directrix. The midpoint between (2,4) and (2,8) is (2,6). This is the vertex.

(h,k) = (2,6)

4p(y-k) = (x-h)^2

4*2(y-6) = (x-2)^2

8(y-6) = (x-2)^2

8 0

4 years ago