15th term
Step-by-step explanation:
A(n)=2+(n-1)(-2)
A(15)=2+(15-1)(-2)
A(15)=2+(14)(-2)
A(15)=2+(-28)
A(15)=2-28
A(15)=-26
18th term
A(n)=2+(n-1)(-2)
A(18)=2+(18-1)(-2)
A(18)=2+(17)(-2)
A(18)=2+(-34)
A(18)=2-34
A(18)=-32
31st term
A(n)=2+(n-1)(-2)
A(31)=2+(31-1)(-2)
A(31)=2+(30)(-2)
A(31)=2+(-60)
A(31)=2-60
A(31)=-58
