Factorise x(squared) + 7x - 30

1 answer:

7 0

X^2+7x-30
what we do is we find what 2 number multiply to get -30 and add to get 7
factor 30
30=2 times 3 times 5
we know that is has to be negative eventually so one is negative and one is positivie so we do2 factors and add
2 times 5=10
10 and -3
add
10-3=7
checks
10 times -3=-30

so we put those in
(x-3)(x+10)
factored

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A recent Harris poll asked a random sample of 1016 adults nation-wide whether or not they smoked cigarettes. 22% said they smoke

photoshop1234 [79]

Answer:

A recent Harris poll asked a random sample of 1016 adults nation-wide whether or not they smoked cigarettes. 22% said they smoked. Based on this sample, can you conclude that...

a.) The expected value for the percent of all adults world-wide who would say they smoked cigarettes is 22%?

b). The expected value for the percent of students at UI who would say they smoked cigarettes is 22%?

c). The expected value for the percent of professors at UI who would say they smoked cigarettes is 22%?

d). The expected value for the percent of all US adults who would say they smoked cigarettes is 22%?

The correct answer is

d).The expected value for the percent of all US adults who would say they smoked cigarettes is 22%?

Step-by-step explanation:

The expected value is arrived at by finding the product of a possible output and the probability that the output will occur and summing up the results. Expected value can be used for investment management to calculate options and make decisions most likely to bring about the desired gain. The random variable provides categorisation of the outcomes of the game while the expected provides the probability of aan outcome

In the above, the source of the sample is nationwide whereby 22 % said they smoked therefore it cannot be applied to a different population that has a different expected value for the same survey.

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2 years ago

Pls help! 50 POINTS!

nirvana33 [79]

Answer:

See below.

Step-by-step explanation:

So we have the equation:

$2x+3y=1470$

To change into the slope-intercept form, we need to isolate the y-variable. Thus, subtract 2x from both sides:

$(2x+3y)-2x=(1470)-2x$

The left side cancels:

$3y=1470-2x$

Now, divide both sides by 3. The left side cancels:

$(3y)/3=(-2x+1470)/3\\y=-\frac{2}{3} x+490$

The slope-intercept form is:

$y=mx+b$

Where m is the slope and b is the y-intercept.

Thus, the slope is -2/3 and the y-intercept is 490.

So, since we already know the y-intercept is 490, plot a point at (0,490).

The slope is too small to use. Thus, multiply the fraction by 100. It is now (-200/300). This means that we move <em>down</em> 200 for every 300 (recall that the slope means rise over run. Thus, we move down 200 for every 300 to the right). Thus, another possible point would be (0+300,490-200) or (300,290). Plot that. Then, connect them.

To write in in function notation, simply substitute the y-variable for the function notation. Our independent variable here is x so we'll use that.

$y=-\frac{2}{3}x+490\\ f(x)=-\frac{2}{3}x+490$

This means that for every x sandwiches made, there is f(x) wraps made for the total sum to be $1,470.

For example, if 105 sandwiches were made, then f(105)=-2/3(105)+490=420 wraps were made for the total profit to be $1,470.

Please refer to the attached graph.

First, since the total profit has now increased, the graph above and to the right of the old graph. This is because Sal needs to sell more sandwiches and wraps. Likewise, because of this, the x- and y-intercepts will also be different. Nevertheless, if converted into the slope-intercept equation, the slope will remain the same.