Question

Write an equation for the nth term of the arithmetic sequence. Then find a20.

Answer 1

Explanation:

`\6.a_(n)=a_(1)+(n-1)d\\a_(1)=-(1)/(2) \\\\d=a_(2)-a_(1)\\d=(1)/(2) -(-(1)/(2) )\\d=(1)/(2) +(1)/(2) =(1+1)/(2) =(2)/(2) =1\\a_(n)=-(1)/(2) +(n-1)(1)\\a_(n)=-(1)/(2) +n-1\\a_(n)=(-1-2)/(2) +n\\a_(n)=n-(3)/(2)`

solve other questions after finding d