Question

Please give me the method this it's urgent

Answer 1

given,

3, -3, 3, -3.

now

a=3

r=-3÷3

r=1

we know that.

sn=ar^n-1

sn=(3) (1)^n-1

sn= (3) ^n-1

sn=3+1n

(sn=4)