Question

For an A.P., t4=12 and its common difference d=-10, then find tn.​

Answer 1

Step-by-step explanation:

t4 or a4 = 12

d = -10

a4 = a + 3d

12 = a + 3(-10)

12 = a - 30

12 + 30 = a

42 = a

now,

tn or an = a + (n - 1 ) d

tn = 42 + ( n - 1 ) (-10)

= 42 - 10n + 10

= 52 - 10n

hope it's helpful for you :)

Answer 2

t4=12

t+(4-1)d=12

t+3d=12

t+3(-10)=12

t-30=12

t=12+30

t=42

tn=t+(n-1)d

tn=42+(n-1)-10

=42-10n+10

=52-10n

hope this helps you....