Find the missing term of the arithmetic sequence: 1,___, 1/5 ?

1 Answer
Jul 2, 2018

a_2=3/5

Explanation:

arithmetic sequence:
a_n=a_1+d

given:

a_1=1
a_2=?
a_3=1/5

so:
a_3=a_1+2d => 1/5=1+2d => 2d=-4/5 => d=-4/10=-2/5
=>
a_2=a_1+d=>a_2=1+(-2/5)=3/5