All categories

2 years ago

Solve for the roots in simplest form by completing the square 6x^2+120x+2070=0

Mathematics

1 answer:

Kitty [74]2 years ago

8 0

Answer:

Step-by-step explanation:

First, we can divide out the common factor, 6

$6x^2 + 120x + 2070 = 0\\x^2 + 20x + 345 = 0\\$

Now we complete the square

$(x^2 + 20x + (\frac{20}{2})^2) + 345 - (\frac{20}{2})^2\\(x^2 + 20x + 100) + 345 - 100\\(x+10)^2 + 245\\$

$(x+10)^2 = -245\\x + 10 = \sqrt{-245}\\x = i\sqrt{245} - 10\\x = -10 \pm i\sqrt{245}$

You might be interested in

Plot two points that are 3units from Point C and also share the same y-coordinate as Point C.

egoroff_w [7]

The two points at a distance of 3 units from C with the same y coordinate are (-3, -5) and (-9, -5).

Step-by-step explanation:

Step 1:

First, we must plot the point C on the graph. Point C is on the third quadrant so the x value and the y value are negative.

The coordinate of C is (-6, -5).

We need to plot two points that are 3 units away from point C but have the same y coordinate i.e. y = -5.

Step 2:

So assume the two other points are A and B.

The y coordinates of A and B are -5. Only the x coordinate varies. So in order to get the coordinates of point A and B, we add and subtract 3 from the x coordinate of point C.

Point A = (-6+3, -5) = (-3,-5).

Point B = (-6-3, -5) = (-9, -5).

So two points at a distance of 3 units from C with the same y coordinate are (-3, -5) and (-9, -5).

6 0

2 years ago

Solve the system by the substitution method. Show your work.<br> 2y - x = 5<br> x^2 + y^2 - 25 = 0

Elza [17]

2y - x = 5
x^2 + y^2 - 25 = 0

x = 2y - 5

(2y-5)^2 + y^2 - 25 = 0
(2y-5)(2y-5) + y^2 - 25 = 0
4y^2 - 20y + 25 + y^2 - 25 = 0
5y^2 - 20y = 0
y = 0 , y = 4

x = 2y - 5 , when y = 0
x = - 5

x = 2y - 5 , when y = 4
x = 8 - 5
x = 3

6 0

2 years ago

Two researchers conducted a study in which two groups of students were asked to answer 42 trivia questions from a board game. Th

denpristay [2]

Answer:

(1) Correct option is B.

(2) Correct option is C.

Step-by-step explanation:

The information provided is:

$n_{1}=200,\ \bar x_{1}=22.7,\ s_{1} = 4.5\\n_{2}=200,\ \bar x_{2}=19.7,\ s_{2} = 4.3$

The (1 - <em>α</em>)% confidence interval for the difference between two mean is:

$CI=\bar x_{1}-\bar x_{2}\pm t_{\alpha/2, (n_{1}+n_[2}-2}\sqrt{\frac{s_{1}^{2}}{n_{1}}+\frac{s_{2}^{2}}{n_{2}} }$

The critical value of <em>t</em> is:

$\alpha /2=0.05/2=0.025$

degrees of freedom $=n_{1}+n_{2}-2=200+200-2=398$

$t_{\alpha/2, n_{1}+n_{2}-2}=t_{0.025, 398}=1.96$

Compute the 95% confidence interval for the difference between two mean as follows:

$CI=22.7-19.7\pm 1.96\sqrt{\frac{4.5^{2}}{200}+\frac{4.3^{2}}{200} }\\=3\pm0.8624\\=(2.1376, 3.8624)\\\approx(2.14, 3.86)$

Thus, the 95% confidence interval, (2.14, 3.86) implies that the true mean difference value is contained in this interval with probability 0.95.

Correct option is B.

The null value of the difference between means is 0.

As the value 0 is not in the interval this implies that there is a difference between the two means, concluding that priming does have an effect on scores.

Correct option is C.

4 0

2 years ago

Determine if the following relations represent y as a function of x.

lana [24]

<h3>Answers:</h3>

A) No, it is not a function
B) Yes it's a function
C) Not a function
D) Yes it's a function
E) Yes it's a function

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

Explanation:

If y has an exponent of 2, 4, 6, etc (basically any even number) then it leads to having inputs with multiple outputs.

Consider something like y^2 = x. If x = 100, then y = 10 or y = -10 are possible. A function can only have exactly one y output for any valid x input. Similar issues happen for things like y^4 = x and so on. So this is why A and C are not functions.

The other equations do not have y values with such exponents, so we can solve for y and have each x input lead to exactly one y output. Therefore, they are functions.

5 0

2 years ago

Describe the effect of the transformation (x,y) to (x,7y)

elena-s [515]

The correct answer is B!

5 0

2 years ago