Question

the 6th term of the sequence is 12 and the sum of the first 6 terms is42 then what the first term and the common difference​

Answer 1

Answer:

a=2, d=2

Step-by-step explanation:

a^6=12

s^6=42

a^6=a+(6-1) d

12=a+5d

5d=12-a ...1

s^6=n/2 [2a+(n-1) d]

42=6/2 (2a+5d)

42/3=(2a+12-a) ... (5d=12-a)

14=12+a

a=2

put tjis value of a in eq 1

5d=12-2

5d=10

d=2