Question

the first term of an AP is 5and comman difference is4 . complete the following activity and find the sum of the 12 terms of the AP

Answer 1

a12=5+11 (4)
=49

s12=n (a+l)÷2
6 (5+49)
54×6
=324

Answer 2

Answer:

Sum of 12 terms of the AP is 324

Step-by-step explanation:

Given: a = 5 ; d=4 ; n =12

Sum of n terms of an AP, Sₙ = $\frac{n}{2}[2a+(n-1)d]$

Substituting the given values, we have

S₁₂ = $\frac{12}{2}[2*5+(12-1)4]$

     = 6[10+44] = 6*54 = 324

∴Sum of 12 terms of the AP is 324