Step-by-step explanation:
x+100°=180°{being straight angle}
x=180-100
x=80°
again,
45°+x+y=180°{sum of angle of triangle}
45+80+y=180
y=180-125°
y=55°
hope it helps.
<span>2x + x = 12
=> x =12/3 =4
so, original number is 84.
</span>
Answer:6018
Step-by-step explanation:
Given Sequence

It represent an A.P. with
first term 
common difference 
So sum of 51 term
![S_n=\frac{n}{2}[2a+(n-1)d]](https://tex.z-dn.net/?f=S_n%3D%5Cfrac%7Bn%7D%7B2%7D%5B2a%2B%28n-1%29d%5D)
![S_{51}=\frac{51}{2}\times [2\times (-282)+(51-1)16]](https://tex.z-dn.net/?f=S_%7B51%7D%3D%5Cfrac%7B51%7D%7B2%7D%5Ctimes%20%5B2%5Ctimes%20%28-282%29%2B%2851-1%2916%5D)
![S_{51}=\frac{51}{2}\times [-564+800]](https://tex.z-dn.net/?f=S_%7B51%7D%3D%5Cfrac%7B51%7D%7B2%7D%5Ctimes%20%5B-564%2B800%5D)
![S_{51}=\frac{51}{2}\times [236]](https://tex.z-dn.net/?f=S_%7B51%7D%3D%5Cfrac%7B51%7D%7B2%7D%5Ctimes%20%5B236%5D)


Distribute to eliminate the parenthesis
x^2 + 2x + 6x + 12 = 60
Combine like terms
x^2 + 8x + 12 = 60
Subtract 60 from both sides
x^2 + 8x - 48 = 0
Factor the equation
(x+12)(x-4)=0
x+12=0
x+4=0
x= -12 and -4