What was the original price of a bookshelf whose price is $16, when there is a sale for 75% off of the original price?

Solving Quadratic Equations using the Square Root Property

Afina-wow [57]

Answer:

$x = -2$ or $x = -5$

Step-by-step explanation:

You need to complete the square before you can take the square root of both sides.

$x^2 + 7x + 10 = 0$

Subtract 10 from both sides.

$x^2 + 7x = -10$

To complete the square, you need to add the square of half of the x-term coefficient to both sides.

The x-term coefficient is 7. Half of that is 7/2. Square it to get 49/4. Now we add 49/4 to both sides of the equation.

$x^2 + 7x + \dfrac{49}{4} = -10 + \dfrac{49}{4}$

$(x + \dfrac{7}{2})^2 = -\dfrac{40}{4} + \dfrac{49}{4}$

$(x + \dfrac{7}{2})^2 = \dfrac{9}{4}$

Now we use the square root property, if

$x^2 = k$ , then

$x = \pm \sqrt{k}$

$x + \dfrac{7}{2} = \pm \sqrt{\dfrac{9}{4}}$

$x + \dfrac{7}{2} = \pm \dfrac{3}{2}$

$x + \dfrac{7}{2} = \dfrac{3}{2}$ or $x + \dfrac{7}{2} = -\dfrac{3}{2}$

$x = -\dfrac{4}{2}$ or $x = -\dfrac{10}{2}$

$x = -2$ or $x = -5$

5 0

3 years ago

As.

Natalka [10]

9514 1404 393

Answer:

4/13 h ≈ 0.308 h
22 9/13 km ≈ 22.7 km

Step-by-step explanation:

Mary and Amaruk are starting 35 -15 = 20 km apart. Their closing speed is 40 +25 = 65 km/h. The time it will take to close the gap between them is ...

t = (20 km)/(65 km/h) = 20/65 h = 4/13 h ≈ 0.308 h

They will pass each other after 4/13 hours, about 18 minutes 28 seconds.

__

In that time, Mary will have increased her distance from Hall Beach by ...

d = (4/13 h)(25 km/h) = 100/13 km = 7 9/13 km

Her distance from Hall Beach when she passes Amaruk will be ...

15 km + 7 9/13 km = 22 9/13 km ≈ 22.7 km . . . . . distance from Hall Beach

6 0

2 years ago

Tell whether the two figures are similar explain you reasoning

seropon [69]

What figures are you talking about, can you post the picture?

6 0

2 years ago

Hello guys I really beg you! my work is due tomorrow and i cant understand it please help! go to my profile then click questions

Korvikt [17]

Answer:

I can help, please send your problems!

7 0

2 years ago

Select the correct answer.

BARSIC [14]

Answer:

D) 4x + 2y ≤ 25 , x + y ≥ 8 is the required system of inequalities

to represent the given situation.

Step-by-step explanation:

Here, let the number of color copies = x

Now, the time taken to print each color copy = 4 minutes

⇒Time taken to print x color copies = x times ( Time taken by each copy)

= 4 (x) = 4x

and let the number gray scale copies = y

The time taken to print each gray scale copy = 2 minutes

⇒Time taken to print y gray scale copy = y times (Time taken by each copy)

= 2 (y) = 2y

Total copies printed = x + y

Maximum time taken to print x color copies and y grayscale copies

= 4x + 2y

So, according to the question:

4x + 2y ≤ 25 ( as maximum allotted time is 25 minutes)

and x + y ≥ 8 (as minimum number of copies is 8)

hence, the above system is the required system of inequalities to represent the given situation.

7 0

2 years ago