Answer:
![\boxed{\sf \ \ \ x^2 + x -72 = 0 \ \ \ }](https://tex.z-dn.net/?f=%5Cboxed%7B%5Csf%20%5C%20%5C%20%5C%20x%5E2%20%2B%20x%20-72%20%3D%200%20%5C%20%5C%20%5C%20%7D)
Step-by-step explanation:
Hello,
We need to use the <u>distributive property</u> which means that for a, b and c real numbers a(b+c)=ab+ac
So here we can write
![x(x+1)=72\\ x*x+x*1=72\\ x^2 + x -72 = 0\\](https://tex.z-dn.net/?f=x%28x%2B1%29%3D72%5C%5C%3C%3D%3E%20x%2Ax%2Bx%2A1%3D72%5C%5C%3C%3D%3E%20x%5E2%20%2B%20x%20-72%20%3D%200%5C%5C)
do not hesitate if you have any question
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:
105
Step-by-step explanation:
60/4= 15
15x7= 105
Answer:
Your answer would be...
30 ft
Hope this helps. Sry if im wrong.
Step-by-step explanation:
3 x 10 = 30 feet