Question

If a = 2 and d =4 then find S20​

Answer 1

Sn=n/2 [a+(n-1) d]

given:

a=2

d=4

n=20

=) S20= 20/2 [2+(20-1) 4]

=) S20= 10 [2+ (19)4]

=) S20= 10 [2+76]

=) S20= 10 (78)

=) S20= 780

Answer 2

Answer:

YOUR ANSWER IS HERE

Step-by-step explanation:

a=2

d=4

n=20

= S²⁰=n/2(2a+(n-1)d)

= s²⁰= 20/2(2(2)+(20-1)4)

= s²⁰= 10(4+(19)4)

= s²⁰= 10(4+76)

= s²⁰= 10(80)

= s²⁰= 800