. If the expressions x + 5, 2x, and 4x −17 represent the first three terms of an arithmetic sequence, then determine the numerical value of the 20th term.

Answer: The value of 20th term is 150.
Step-by-step explanation:
Since we have given that
[tex]x+5,2x,4x-17[/tex]
Since they are in AP.
So, we know that
[tex]2b=a+c\\\\2(2x)=x+5+4x-17\\\\4x=5x-12\\\\4x-5x=-12\\\\-x=-12\\\\x=12[/tex]
So, the first term would be :
[tex]x+5=12+5=17=a[/tex]
common difference would be :
[tex]2x-(x+5)\\\\=2x-x-5\\\\=x-5\\\\=12-5\\\\=7[/tex]
So, the value of 20th term would be :
[tex]a_{20}=a+19d=17+19\times 7=17+133=150[/tex]
Hence, the value of 20th term is 150.