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3 years ago

When is it most appropriate to use the completing the square method to solve a quadratic equation?

Mathematics

1 answer:

mash [69]3 years ago

4 0

Answer:

Don't forget to include a ± sign in your equation once you have taken the square root. Next, if the coefficient of the squared term is 1 and the coefficient of the linear (middle) term is even, completing the square is a good method to use. Finally, the quadratic formula will work on any quadratic equation.

Step-by-step explanation:

x² + 4x = 15 can be solved best using the completing the square method.

2x(x−3)=0 can be best solved using the zero product property.

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Five hundred randomly selected working adults living in Calgary, Canada were asked how long, in minutes, their typical daily com

Anarel [89]

Answer:

90% confidence interval for the mean commute time of working adult Calgary residents is between a lower limit of 26.72 minutes and an upper limit of 30.28 minutes.

Step-by-step explanation:

Confidence Interval = Mean + or - Error margin (E)

mean = 28.5 minutes

sd = 24.2 minutes

n = 500

degree of freedom = n - 1 = 500 - 1 = 499

confidence level = 90%

t-value corresponding to 499 degrees of freedom and 90% confidence level = 1.64801

E = t × sd/√n = 1.64801 × 24.2/√500 = 1.78

Lower limit = mean - E = 28.5 - 1.78 = 26.72 minutes

Upper limit = mean + E = 28.5 + 1.78 = 30.28 minutes

90% confidence interval is between 26.72 and 30.28 minutes.

5 0

3 years ago

QUICK PLEASE !!!!!

Leni [432]

Answer:

Step-by-step explanation:

The slope-intercept form of an equation of a line:

$y=mx+b$

m - slope

b - y-intercept

The formula of a slope:

$m=\dfrac{y_2-y_1}{x_2-x_1}$

==============================================

From the table we have :

x = 1 → y = 6

x = 2 → y = 9

x = 3 → y = 12

x = 4 → y = 15

Calculate the slope (choice any two pairs, and calculate the slope):

(1, 6), (2, 9)

$m=\dfrac{9-6}{2-1}=\dfrac{3}{1}=3$

We have the equation:

$y=3x+b$

Put the coordinates of the point (1, 6) to the equation, and solve it for b:

$6=3(1)+b$

$6=3+b$ <em>subtract 3 from both sides</em>

$3=b\to b=3$

Finally:

$y=3x+3$

3 0

3 years ago

A dartboard has 20 equally divided wedges and you are awarded the number of points in the section of your dark lands in if you a

Leto [7]

Answer:

$Pr =0.75$

Step-by-step explanation:

Given

See attachment for wedge

Required

$P(x > 5)$

The sample space of the wedge is:

$S = \{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20\}$

$n(S) = 20$

The outcomes greater than 5 are:

$x > 5 = \{6,7,8,9,10,11,12,13,14,15,16,17,18,19,20\}$

$n(x>5) =15$

So, the probability is:

$Pr =\frac{(n(x>5)}{n(S)}$

This gives:

$Pr =\frac{15}{20}$

$Pr =0.75$

6 0

3 years ago

If 17 bumper stickers cost $13.94, then 11 bumper stickers cost?

Lady bird [3.3K]

$9.02 because if you divide 13.94 by 17 you get 0.82, the price per sticker, then multiply that by 11 to find the price of 11 stickers.

6 0

3 years ago

Read 2 more answers

Find the perimeter of a quadrilateral with vertices at R (-2, 1), S (-5, 5), T (2, 5), U (5, 1). Round your answer to the neares

Nezavi [6.7K]

Check the picture below.

now, you can pretty much count the units off the grid for the segments ST and RU, so each is 7 units long, and are parallel, meaning that the other two segments are also parallel, and therefore the same length each.

so we can just find the length for hmmmm say SR, since SR = TU, TU is the same length,

$\bf ~~~~~~~~~~~~\textit{distance between 2 points}
\\\\
S(\stackrel{x_1}{-2}~,~\stackrel{y_1}{1})\qquad 
R(\stackrel{x_2}{-5}~,~\stackrel{y_2}{5})\qquad \qquad 
% distance value
d = \sqrt{( x_2- x_1)^2 + ( y_2- y_1)^2}
\\\\\\
SR=\sqrt{[-5-(-2)]^2+[5-1]^2}\implies SR=\sqrt{(-5+2)^2+(5-1)^2}
\\\\\\
SR=\sqrt{(-3)^2+4^2}\implies SR=\sqrt{25}\implies SR=5$

sum all segments up, and that's perimeter.

6 0

3 years ago