Question

If anyone can help me on this​

Answer 1

120

Explanation:

`nth = a + (n - 1)d`

that above is the formula for nth term.

since a is the first term then a =3 , n is 21 , and d which is the common difference is going to be 2. since d is gotten by 5-3, 7-5 , 9-7.

with all the parameters,

21st term = 3(21-1)2

=3(20)2

=3×20×2

= 120

therefore the 21st term is 120