Question

Frist term an AP is 5 & seventh term is -7,find common difference

Answer 1

HERE ,A = 5
A7=-7
OR A+6D = -7

PUT VALUE OF A
5+6D= -7
6D=-7-5
6D= -12
D= -2

Answer 2

a=5
a7=-7
a+6d=-7. (1)
putting the value of a in eqn 1
5+6d=-7
6d=-7-5
6d=-12
d=-2