Question

for an A.P a=20 and d= -4 find tn

Answer 1

Step-by-step explanation:

$a = 20 \\ d = - 4 \\ \\ T_{n} = a + (n - 1)d \\ T_{n} = 20 + (n - 1) - 4 \\ T_{n} = 20 + ( - 4n) + 4 \\ T_{n} = 20 - 4n + 4 \\ T_{n} = 24 - 4n \\ T_{n} = \underline{ \underline{ 4(6 - n)}}$