Answer:
-11
Step-by-step explanation:
Given
Use properties:
Thus,
[ Answer ]
[ Explanation ]
Area = 1420
Width = 
Area For Rectangle: Length · Width
Use division to find width:
1420 ÷
Convert mixed numbers to fractions:
1420 = 
= 
÷
Use mixed multiplication:
= 
Simplify:
= 
![\boxed{[ \ Eclipsed \ ]}](https://tex.z-dn.net/?f=%5Cboxed%7B%5B%20%5C%20Eclipsed%20%5C%20%5D%7D)
So lets get to the problem
<span>165°= 135° +30° </span>
<span>To make it easier I'm going to write the same thing like this </span>
<span>165°= 90° + 45°+30° </span>
<span>Sin165° </span>
<span>= Sin ( 90° + 45°+30° ) </span>
<span>= Cos( 45°+30° )..... (∵ Sin(90 + θ)=cosθ </span>
<span>= Cos45°Cos30° - Sin45°Sin30° </span>
<span>Cos165° </span>
<span>= Cos ( 90° + 45°+30° ) </span>
<span>= -Sin( 45°+30° )..... (∵Cos(90 + θ)=-Sinθ </span>
<span>= Sin45°Cos30° + Cos45°Sin30° </span>
<span>Tan165° </span>
<span>= Tan ( 90° + 45°+30° ) </span>
<span>= -Cot( 45°+30° )..... (∵Cot(90 + θ)=-Tanθ </span>
<span>= -1/tan(45°+30°) </span>
<span>= -[1-tan45°.Tan30°]/[tan45°+Tan30°] </span>
<span>Substitute the above values with the following... These should be memorized </span>
<span>Sin 30° = 1/2 </span>
<span>Cos 30° =[Sqrt(3)]/2 </span>
<span>Tan 30° = 1/[Sqrt(3)] </span>
<span>Sin45°=Cos45°=1/[Sqrt(2)] </span>
<span>Tan 45° = 1</span>
Answer:
The number is 9.
Step-by-step explanation:
Lets write this as an equation first. We'll substitute the number for the variable <em>x</em>.
80 - 3x = 5x + 8
First, let's add 3x to both sides.
80 - 3x + 3x = 5x + 3x + 8
80 = 8x + 8
Next, let's subtract 8 from both sides.
80 - 8 = 8x + 8 - 8
72 = 8x
Finally, let's divide both sides by 8.
72/8 = 8x/8
9 = x
<em>"x" is 9.</em>
<em>So the secret number is 9.</em>
P.S.
This is my first answer to a Brainly question so please don't complain!
