Sir here is one mistake in 7th Ter exceeds the 5th term by 12Also,an=a

This question was asked in Ex 5.2, 16

Sir here is one mistake in 7th Ter exceeds the 5th term by 12

Also,
an=a (n-1)d
a7=a (7-1)d
a7=a 6d

Here written wrong sir