The square of a number is 12 less than 7 times he number. what is the number?

Susan and Mark are standing at different places on a beach and watching a bird. The angles of elevation they make are 20º and 50

Mandarinka [93]

Answer:

The bird is 2.44km high

Step-by-step explanation:

Hello,

To solve this question, we need to understand how they are and we can only get this with a correct pictorial diagram.

See attached document for better understanding.

From the first diagram, we understand that the bird is between them and also on top of them.

Assuming Susan, Mark and the bird all form a triangle at each other and the bird at the top, we can divide the the triangle into two equal parts.

But before then, we should know that sum of angles in a triangle is equal to 180°

Therefore,

20° + 50° + b° = 180

70° + b = 180

b = 180° - 70°

b = 110°

Dividing angle b into two equal parts = 55° on each side.

See the last attached document for better illustration.

Using SOHCAHTOA, we can find the adjacent of the triangle which corresponds to the height of the bird.

We have opposite = 3.4km and we're looking for adjacent. We can use tangent of the angle to find the adjacent.

Tanθ = opposite / adjacent

Tan 55° = 3.5 / adj

Adjacent = 3.5 / tan55

Adjacent = 3.5 / 1.43

Adjacent = 2.44km

The height of the bird is 2.44km

7 0

3 years ago

<img src="https://tex.z-dn.net/?f=Simplify%3A%20%5Cfrac%7B%205%C3%97%2825%29%5E%7Bn%2B1%7D%20-%2025%20%C3%97%20%285%29%5E%7B2n%7

Katen [24]

$\green{\large\underline{\sf{Solution-}}}$

<u>Given expression is </u>

$\rm :\longmapsto\:\dfrac{5 \times {25}^{n + 1} - 25 \times {5}^{2n} }{5 \times {5}^{2n + 3} - {25}^{n + 1} }$

can be rewritten as

$\rm \: = \: \dfrac{5 \times { {(5}^{2} )}^{n + 1} - {5}^{2} \times {5}^{2n} }{5 \times {5}^{2n + 3} - {( {5}^{2} )}^{n + 1} }$

We know,

$\purple{\rm :\longmapsto\:\boxed{\tt{ {( {x}^{m} )}^{n} \: = \: {x}^{mn}}}} \\$

And

$\purple{\rm :\longmapsto\:\boxed{\tt{ \: \: {x}^{m} \times {x}^{n} = {x}^{m + n} \: }}} \\$

So, using this identity, we

$\rm \: = \: \dfrac{5 \times {5}^{2n + 2} - {5}^{2n + 2} }{{5}^{2n + 3 + 1} - {5}^{2n + 2} }$

$\rm \: = \: \dfrac{{5}^{2n + 2 + 1} - {5}^{2n + 2} }{{5}^{2n + 4} - {5}^{2n + 2} }$

can be further rewritten as

$\rm \: = \: \dfrac{{5}^{2n + 2 + 1} - {5}^{2n + 2} }{{5}^{2n + 2 + 2} - {5}^{2n + 2} }$

$\rm \: = \: \dfrac{ {5}^{2n + 2} (5 - 1)}{ {5}^{2n + 2} ( {5}^{2} - 1)}$

$\rm \: = \: \dfrac{4}{25 - 1}$

$\rm \: = \: \dfrac{4}{24}$

$\rm \: = \: \dfrac{1}{6}$

<u>Hence, </u>

$\rm :\longmapsto\:\boxed{\tt{ \dfrac{5 \times {25}^{n + 1} - 25 \times {5}^{2n} }{5 \times {5}^{2n + 3} - {25}^{n + 1} } = \frac{1}{6} }}$

4 0

2 years ago

Please can you help me with this

Orlov [11]

4a-87=a

3a=87

a=87/3=29

5 0

3 years ago

Select the digit in the ten thousand place for 542,970

just olya [345]

Answer:

The digit in the ten thousand place is 4 in 542,970

Step-by-step explanation:

6 0

2 years ago

Read 2 more answers

Find the scale factor from DEF to ABC

Serjik [45]

Answer:

³/2 (1.5)

Step-by-step explanation:

∆DEF was enlarged to get ∆ABC. The scale factor would be:

The ratio of any of the side length of ∆ABC to the corresponding side length of ∆DEF.

Thus,

BC:EF = 12:8

= 12/8

= 3/2 = 1.5

Scale factor from ∆DEF to ∆ABC is ³/2 or 1.5

8 0

2 years ago