Question

find the sum of first 10 terms of the AP 2, 7, 12.............​

Answer 1

Answer:

S10=245

Step-by-step explanation:

Given :t1=2, t2=7, t3=12

Given :t1=2, t2=7, t3=12t1=a=2,n=10, d=t2-t1=7-2=5

Given :t1=2, t2=7, t3=12t1=a=2,n=10, d=t2-t1=7-2=5by using formula,

Given :t1=2, t2=7, t3=12t1=a=2,n=10, d=t2-t1=7-2=5by using formula,Sn=n/2[2a+(n-1)d]

Given :t1=2, t2=7, t3=12t1=a=2,n=10, d=t2-t1=7-2=5by using formula,Sn=n/2[2a+(n-1)d]substitute the values,

S10=10/2[2*2+(10-1)5]

S10=10/2[4+9*5]

S10=10/2*49

S10=5*49

S10=245