Question

We have ap is given a15=22 and a12+a7=66find the common difference

Answer 1

Answer:

D=-2

Step-by-step explanation:

a15=a+14d=22.........1

a12+a7=66

a+11d+a+6d=66

2a+17d=66.......2

1×2

2a+28d=44......3

2a+17d=66.......2

3-2

change the sign

so we can get

11d=-22

d=-22/11

d=-2