A CD usually sells for $12.00. If the CD is 30% off, and sales tax is 5%, what is the total price of the CD, including tax?

The area of two similar triangles are 50dm^2 and 32dm^2. The sum of their perimeters is 117dm. What us the perimeters of each of

Kay [80]

Answer:

Perimeter of one triangle is 65 dm

Perimeter of other triangle is 52 dm

Step-by-step explanation:

Please remember the concept

If sides are in the ratio of a:b

Then the area in the ratio of $a^{2} :b^{2}$

It is given sum of their perimeter is 117.

Let the small triangle has perimeter as x.

So, perimeter of big triangle is 117-x.

So, we can set up equation as

$\frac{50}{32} =\frac{x^{2} }{(117-x)^{2} }$

Cross multiply

50(117-x)^2 =32x^2

Expand the left side

50 $(13689 -234x+x^{2} )$ = $32x^{2}$

Distribute the left side

684450-11700x+ $50x^{2}$ = $32x^{2}$

Subtract both sides $32x^{2}$ and rewrite it $18x^{2} -11700x+684450=0$

Solve this quadratic for x.

Divide both sides of the equation by 18 to simplify.

$x^{2}$ -650 x+38025=0

Now, if possible let's factor

Find two integers whose multiplication is 38025 but adds to -650.

-65 and -585 works.

So, we can rewrite it as

(x -65)(x-585) =0

Solve them using zero product property

x=65, x=585

So, x=65 works here.

So, perimeter of one triangle is 65 dm

Perimeter of other triangle is 117-65= 52 dm

5 0

3 years ago

What is the perimeter P of △DEF to the nearest whole number?

inna [77]

Answer:

Can you please tell me what is the area of the given triangle?

3 0

3 years ago

What is 1.5 as a ratio

Kitty [74]

Answer: 3/2

Step-by-step explanation:

3 0

3 years ago

B is the midpoint of AC and E' is the midpoint of BD. If A(-9,-4), C(-1, 6), and E(-4,-3), find the coordinates of D.

Ipatiy [6.2K]

The coordinates for D are (-4, -7)

First we must locate point B as it is vital to finding the midpoint of BD. To do this, we take the average of the endpoints AC since B is its midpoint.

x values = -9 + 1 = -8
Then divide by 2 for the average -8/2 = -4

y values = -4 + 6 = 2
Then divide by 2 for the average 2/2 = 1

Therefore B must be (-4, 1)

Now we know the values of E must be the average of B and D. So we can write equations for each coordinate since we know they are averages.

x - values = (Bx + Dx)/2 = Ex
(-4 + Dx)/2 = -4 ---> multiply both sides by 2
-4 + Dx = -8 ---> add -4 to both sides
Dx = -4

y - values = (By + Dy)/2 = Ey
(1 + Dy)/2 = -3 ---> multiply both sides by 2
1 + Dy = -6 ---> subtract 1 from both side
Dy = -7

So the coordinates for D must be (-4, -7)

5 0

3 years ago

Read 2 more answers

The height in feet is modelled by the function below, where the t is in

Sedaia [141]

The object reaches the lowest height at 5 seconds

<h3>How to determine the time?</h3>

The function is given as:

f(t) = -2t² +22t + 6

Differentiate the function

f'(t) = -4t +22

Set to 0

-4t +22 = 0

Subtract 22 from both sides

-4t = -22

Divide both sides by -4

t = 5.5

Remove decimal points

t = 5

Hence, the object reaches the lowest height at 5 seconds

Read more about quadratic functions at:

brainly.com/question/1214333

#SPJ1

6 0

2 years ago