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3 years ago

What is the justification for each step in the solution of the equation?

Mathematics

2 answers:

jeka57 [31]3 years ago

6 0

13x−4=−36−27x+12: Distributive property

13x−4=−24−27x: Combine like terms

40x=−20: Addition Property of equality

Crazy boy [7]3 years ago

6 0

<h2>Answer with Step-by-step explanation:</h2>

13x−4= −9(4+3x)+12 (Given)

13x−4= −36−27x+12 (Distributive property: -9(4+3x)= -36-27x)

13x−4= −24−27x (combining like terms on each side: -36+12= -24)

40x−4=−24 (Addition Property of Equality: adding 27x on both sides )

40x= −20 (Addition Property of Equality: adding 4 on both sides )

x= −1/2 (Division Property of Equality: dividing both sides by 40)

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Use the formula r=log^10L, where r is the measurement of the Richter scale and l is the intensity, to find the Richter scale mea

Alborosie

Answer:

9.264817823

Step-by-step explanation:

If you use your calculator, press the log function button. Then type this (10 x 184,000,000). It will now give you your final answer.

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3 years ago

Luis wants to buy a skateboard that usually sells for $79.08. All merchandise is discounted by 12%. What is the total cost of th

FrozenT [24]

Answer:

$74.96

Step-by-step explanation:

$79.80 × 0.12 = 9.576 (discount)

$79.80 - $9.576 = $70.224

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3 years ago

Solve x2 - 8x = 20 by completing the square. Which is the solution set of the equation?

Artyom0805 [142]

Answer:

{-2,10}

Step-by-step explanation:

x^2 - 8x = 20

Take the coefficient of x

-8

Divide by 2

-8/2 =-4

Square it

(-4)^2 =16

Add this to each side

x^2 - 8x+16 = 20+16

x^2 - 8x+16 = 36

The left hand side becomes( x + (-8/2) )^2

(x - 4)^2 = 36

Take the square root of each side

sqrt((x - 4)^2) =±sqrt( 36)

x-4 = ±6

Add 4 to each side

x-4+4 = 4±6

x = 4±6

x = 4+6 x = 4-6

x = 10 x = -2

3 0

4 years ago

A small regional carrier accepted 19 reservations for a particular flight with 17 seats. 14 reservations went to regular custome

Ludmilka [50]

Answer:

(a) The probability of overbooking is 0.2135.

(b) The probability that the flight has empty seats is 0.4625.

Step-by-step explanation:

Let the random variable X represent the number of passengers showing up for the flight.

It is provided that a small regional carrier accepted 19 reservations for a particular flight with 17 seats.

Of the 17 seats, 14 reservations went to regular customers who will arrive for the flight.

Number of reservations = 19

Regular customers = 14

Seats available = 17 - 14 = 3

Remaining reservations, n = 19 - 14 = 5

P (A remaining passenger will arrive), p = 0.52

The random variable X thus follows a Binomial distribution with parameters n = 5 and p = 0.52.

(1)

Compute the probability of overbooking as follows:

P (Overbooking occurs) = P(More than 3 shows up for the flight)

$=P(X>3)\\\\={5\choose 4}(0.52)^{4}(1-0.52)^{5-4}+{5\choose 5}(0.52)^{5}(1-0.52)^{5-5}\\\\=0.175478784+0.0380204032\\\\=0.2134991872\\\\\approx 0.2135$

Thus, the probability of overbooking is 0.2135.

(2)

Compute the probability that the flight has empty seats as follows:

P (The flight has empty seats) = P (Less than 3 shows up for the flight)

$=P(X$

Thus, the probability that the flight has empty seats is 0.4625.

4 0

3 years ago

Find all solutions of each equation on the interval 0 ≤ x < 2π.

Korvikt [17]

Answer:

$x = 0$ or $x = \pi$ .

Step-by-step explanation:

How are tangents and secants related to sines and cosines?

$\displaystyle \tan{x} = \frac{\sin{x}}{\cos{x}}$ .

$\displaystyle \sec{x} = \frac{1}{\cos{x}}$ .

Sticking to either cosine or sine might help simplify the calculation. By the Pythagorean Theorem, $\sin^{2}{x} = 1 - \cos^{2}{x}$ . Therefore, for the square of tangents,

$\displaystyle \tan^{2}{x} = \frac{\sin^{2}{x}}{\cos^{2}{x}} = \frac{1 - \cos^{2}{x}}{\cos^{2}{x}}$ .

This equation will thus become:

$\displaystyle \frac{1 - \cos^{2}{x}}{\cos^{2}{x}} \cdot \frac{1}{\cos^{2}{x}} + \frac{2}{\cos^{2}{x}} - \frac{1 - \cos^{2}{x}}{\cos^{2}{x}} = 2$ .

To simplify the calculations, replace all $\cos^{2}{x}$ with another variable. For example, let $u = \cos^{2}{x}$ . Keep in mind that $0 \le \cos^{2}{x} \le 1 \implies 0 \le u \le 1$ .