Answer:
first term is 8 and common difference d is -4
Step-by-step explanation:
nth term of an arithmetic sequence is: aₙ=12-4n
First term is putting n=1:
aₙ=12-4n
a₁=12-4(1)
a₁=12-4
a₁=8
So, first term a₁= 8
Now finding second term to find common difference
Second term is: n=2
aₙ=12-4n
a₂=12-4(2)
a₂=12-8
a₂=4
So, second term is: 4
The common difference is: a₂-a₁= 4-8 = -4
So, first term is 8 and common difference d is -4 if nth term is 12-4n
