Question

given a =2, d = 8 ,an = 90, find n and an ​

Answer 1

Answer:

n=45, an=90(already given)

Answer 2

Answer:

an = a + ( n- 1 ) d

90 = 2+ ( n-1) 8

90-2 = ( n-1) 8

88 /8 = (n -1)

11 = n-1

n= 1+11

n= 12