Answer:
[tex]a_2_0=-65[/tex]
Step-by-step explanation:
As we can see, the sequence starts from 30 and decreases by 5 each time. So, one possible formula for that sequence could be:
[tex]a_n=35-5n\hspace{10}n\in N[/tex]
Let's confirm the formula by evaluating the first 4 terms:
[tex]a_1=35-5(1)=35-5=35\\a_2=35-5(2)=35-10=25\\a_3=35-5(3)=35-15=20\\a_4=35-5(4)=35-20=15[/tex]
Finally evaluating n=20:
[tex]a_2_0=35-5(20)=35-100=-65[/tex]
