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3 years ago

What are the possible values for x in the equation 4x^2=64

2 answers:

4 0

4 x² = 64

Divide each side by 4 : x² = 16

Take the square root
of each side: x = √16

 x = + 4
and
 x = - 4 .

ss7ja [257]3 years ago

4 0

4x^2=64 divide both sides by 4 x^2=16 x= +4, -4 hope this helps

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3x+2y=6 and y=-3/2x+5

love history [14]

In order to solve for parallel, perpendicular, or neither, you have to look at the slope.

If the slope is the same for both equations, it is most likely parallel.
If it's the reciprocal (Where you flip the number and add change the signs. For example, the reciprocal of 1/2 is -2)
If the slope is not the same or the reciprocal, then it is neither.

So for the first equation, your slope is:
3x+2y=6
2y=-3x+6
y=-3/2x+3 The equation y=mx+b can help you here, where m is the slope.
Your slope is -3/2

For the second equation, your slope is -3/2 since y=-3/2x+5 is already in y=mx+b form and m is the slope.

Since both slopes are -3/2, then you have parallel equations!

(Be careful though, sometimes it will have the same slope but there will also be the same y-intercept. If that happens, it's no longer parallel, but it's the same equation. Such as y=-3/2x+1 and y=-3/2x+1. In this case there will be infinite solutions, but parallel equations have no solutions.)

I hope this helps!! Please ask if you have more questions!

6 0

3 years ago

What do letters have to do in bisectors.

Alborosie

Answer:

The definition of a bisector is something that cuts an object into two equal parts. This "something" is usually a line or a segment.

Step-by-step explanation:

An angle bisector of a triangle divides the opposite side into two segments that are proportional to the other two sides of the triangle. to create similar triangles. ... An angle bisector is a ray in the interior of an angle forming two congruent angles.

6 0

3 years ago

An experiment was conducted to observe the effect of an increase in temperature on the potency of an antibiotic. Three 1-ounce p

ludmilkaskok [199]

Answer:

a) $y=-0.317 x +46.02$

b) Figure attached

c) $S^2=\hat \sigma^2=MSE=\frac{190.33}{10}=19.03$

Step-by-step explanation:

We assume that th data is this one:

x: 30, 30, 30, 50, 50, 50, 70,70, 70,90,90,90

y: 38, 43, 29, 32, 26, 33, 19, 27, 23, 14, 19, 21.

a) Find the least-squares line appropriate for this data.

For this case we need to calculate the slope with the following formula:

$m=\frac{S_{xy}}{S_{xx}}$

Where:

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}{n}$

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}$

So we can find the sums like this:

$\sum_{i=1}^n x_i = 30+30+30+50+50+50+70+70+70+90+90+90=720$

$\sum_{i=1}^n y_i =38+43+29+32+26+33+19+27+23+14+19+21=324$

$\sum_{i=1}^n x^2_i =30^2+30^2+30^2+50^2+50^2+50^2+70^2+70^2+70^2+90^2+90^2+90^2=49200$

$\sum_{i=1}^n y^2_i =38^2+43^2+29^2+32^2+26^2+33^2+19^2+27^2+23^2+14^2+19^2+21^2=9540$

$\sum_{i=1}^n x_i y_i =30*38+30*43+30*29+50*32+50*26+50*33+70*19+70*27+70*23+90*14+90*19+90*21=17540$

With these we can find the sums:

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}=49200-\frac{720^2}{12}=6000$

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}=17540-\frac{720*324}{12}{12}=-1900$

And the slope would be:

$m=-\frac{1900}{6000}=-0.317$

Nowe we can find the means for x and y like this:

$\bar x= \frac{\sum x_i}{n}=\frac{720}{12}=60$

$\bar y= \frac{\sum y_i}{n}=\frac{324}{12}=27$

And we can find the intercept using this:

$b=\bar y -m \bar x=27-(-0.317*60)=46.02$

So the line would be given by:

$y=-0.317 x +46.02$

b) Plot the points and graph the line as a check on your calculations.

For this case we can use excel and we got the figure attached as the result.

c) Calculate S^2

In oder to calculate S^2 we need to calculate the MSE, or the mean square error. And is given by this formula:

$MSE=\frac{SSE}{df_{E}}$

The degred of freedom for the error are given by:

$df_{E}=n-2=12-2=10$

We can calculate:

$S_{y}=\sum_{i=1}^n y^2_i -\frac{(\sum_{i=1}^n y_i)^2}{n}=9540-\frac{324^2}{12}=792$

And now we can calculate the sum of squares for the regression given by:

$SSR=\frac{S^2_{xy}}{S_{xx}}=\frac{(-1900)^2}{6000}=601.67$

We have that SST= SSR+SSE, and then SSE=SST-SSR= 792-601.67=190.33[/tex]

So then :

$S^2=\hat \sigma^2=MSE=\frac{190.33}{10}=19.03$

5 0

3 years ago

Which of the following equations is represented by the figure?

Aleonysh [2.5K]

Your answer should be D.

8 0

3 years ago

Write equivalent fractions for 1 2/3 and 1 7/8 using 24 as the common denominator 2 24 7 1 0

NARA [144]

Answer:

2×8=16

7×3=21

2/3 + 7/8 = 16/24 + 21/24

7 0

2 years ago