Find the sum of first 25 terms of the A.P 30,26,22
Answers
Answered by
1
Step-by-step explanation:
S25=25÷2[2×30+(25-1)×(-4)]
=25÷2[60+24×(-4)]
=25÷2(60-96)
=25÷2×(-36)
=12.5×(-36)
S25 = -450
Similar questions