Question

(i) 1 + 7 +13 + 19 + ..... to 40 terms.​

Answer 1

Step-by-step explanation:

1+7+13+19+(-0)=40

I hope it's help you please mark as brainlist

Answer 2

Step-by-step explanation:

$an = a + (n - 1) \\ = 1 + (40 - 1)6 \\ = 1 + 39 \times 6 \\ = 1 + 234 = 235$

Sn= n/2(a+l)

=40/2(1+235)

=20 × 236

= 5720