Question

in What is of an A 40 the A.P. sun of the first 20 terms a =4 and t20 36? B) 200 c) 400 D800m​

Answer 1

Answer:

400

Step-by-step explanation:

AP:4,8,12,16......20

a=4 d=4 t20=36 Sn=?

Sn=n/2 (t1+tn)

Sn =20/2(4+36)

Sn=10(40)

Sn=400