Question

find the common difference of an ap whose first term is 100 and the sum of whose first term 6 terms is 5 times the sum of the next 6 terms​

Answer 1

Answer:

-200

Step-by-step explanation:

first term(a) =100

5(sum of first 6 terms=(sum of next 6 terms)

5(100*6+d+2d+3d+4d+5d)=(100*6+6d+7d+8d+9d+10d+11d+12d)

3000+75d=600+63d

12d=-2400

d=-200