Question

if nth term of ap is an=5n-3 find the sum of first term​

Answer 1

Answer:

2

Step-by-step explanation:

an = 5n - 3

Let n = 1

a(1) = 5(1) - 3

a = 2

Let n = 2

a(2) = 5(2) - 3

a2 = 7

Therefore, d = a2 - a1 = 7 - 2 = 5

d = 5

S1 = 2a + (n - 1) d × (n/2)

S1 = 2(2) + (1 - 1) (5) × (1/2)

S1 = 4 × (1/2)

S1 = 2