Question

of for any AP,
d=7 what is the value of t18 - t13​

Answer 1

common difference = d = 7

first term = a = a

number of the term = n

Tn = a+(n-1)d

T18 = a+(18-1)7

T18 = a+(17)7

T18 = a+119

Tn = a+(n-1)d

T13 = a+(13-1)7

T13 = a+(12)7

T13 = a+84

so,

T18 - T13

= (a+119)-(a+84)

= a+119-a-84

= 119-84

= 35

so 35 is the answer

Answer 2

d=7

t18=a+17d

=a+17*7

=a+119

t13=a+12d

=a+12×7=a+84

A/q

a+119-(a+84)=a+119-a-84=119-84=35