Question

find rth term of an A.P whose sum of n terms are 2n+3^2

Answer 1

2n + 3² = 0
2n + 9 = 0
2n = -9
n = -9 / 2

Answer 2

$2n + 3 x{2} = 0 \\ 2n + 9 = 0 \\ 2n = - 9 \\ n = - 9 \div 2 \\ n = 4.5$