Step-by-step explanation:
⇒12)It is an arithmetic sequence.
    d=2-1=3-2=4-3=1
     a(n) = a +(n-1)d
     a(n) = 1+(n-1)1
The next three terms:
a(6) = 1+(6-1)1=6
a(7) = 1+(7-1)1=7
a(8) = 1+(8-1)1=8
⇒13)It is an arithmetic sequence.
    d=0-3=-3-0=-6+3=-3
     a(n) = a +(n-1)d
     a(n) = 3+(n-1)-3
The next three terms:
 a(5) = 3+(5-1)-3=-9
 a(6) = 3+(6-1)-3=-12
 a(7) = 3+(7-1)-3=-15
⇒14)It is <u>not </u>an arithmetic sequence.
⇒15) a(50) = 10 +(50-1)5
                   =<u>255</u>
<u>I hope this helps</u>
<u />
 
        
             
        
        
        
Answer:
4.8
Step-by-step explanation:
You just subtract to solve for d so,
8.2 = 3.4 + d
-3.4   -3.4
4.8 = d
 
        
             
        
        
        
Check the picture below.
now, we have a triangle with all three sides, thus we can use Heron's Area Formula on the triangle.
![\bf \qquad \textit{Heron's area formula} \\\\ A=\sqrt{s(s-a)(s-b)(s-c)}\qquad \begin{cases} s=\frac{a+b+c}{2}\\[-0.5em] \hrulefill\\ a=10\\ b=26.695\\ c=22\\ s=29.3475 \end{cases} \\\\\\ A=\sqrt{29.3475(29.3475-10)(29.3475-26.695)(29.3475-22)} \\\\\\ A=\sqrt{29.3475(19.3475)(2.6525)(7.3475)}\implies A\approx \sqrt{11066.007} \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ ~\hfill A\approx 105.195~\hfill](https://tex.z-dn.net/?f=%5Cbf%20%5Cqquad%20%5Ctextit%7BHeron%27s%20area%20formula%7D%20%5C%5C%5C%5C%20A%3D%5Csqrt%7Bs%28s-a%29%28s-b%29%28s-c%29%7D%5Cqquad%20%5Cbegin%7Bcases%7D%20s%3D%5Cfrac%7Ba%2Bb%2Bc%7D%7B2%7D%5C%5C%5B-0.5em%5D%20%5Chrulefill%5C%5C%20a%3D10%5C%5C%20b%3D26.695%5C%5C%20c%3D22%5C%5C%20s%3D29.3475%20%5Cend%7Bcases%7D%20%5C%5C%5C%5C%5C%5C%20A%3D%5Csqrt%7B29.3475%2829.3475-10%29%2829.3475-26.695%29%2829.3475-22%29%7D%20%5C%5C%5C%5C%5C%5C%20A%3D%5Csqrt%7B29.3475%2819.3475%29%282.6525%29%287.3475%29%7D%5Cimplies%20A%5Capprox%20%5Csqrt%7B11066.007%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20%5Crule%7B34em%7D%7B0.25pt%7D%5C%5C%5C%5C%20~%5Chfill%20A%5Capprox%20105.195~%5Chfill)
 
        
             
        
        
        
First find the gradient of the line
Change in y/change in x
-3–3/-3-3
0/-6 
=0 ( so the gradient m is equal to zero) 
Y=0x+c
Input the coordinates of one point to find c
-3=(0*3)+c
-3=c
So the equation is 
Y= -3
        
             
        
        
        
Im guessing the largest side of the triangle, i mean cmon. its the largest.