Question

Find the 31st term of the AP 7,13,19,…… Write the first term and common difference of the AP -5,-1,3,7,…… . In the following AP,find the missing term 7,-----, 47

Answer 1

AP : 7 , 13 , 19

first term , a = 7

common difference , d = 13 - 7 = 6

an = a + (n-1) d

= 7 + ( 31 - 1 ) 6

= 7 + 30 × 6

= 7 + 180

a31 = 187

AP : -5 , -1 , 3 , 7

first term , a = -5

common difference , d = -1 - (-5) = -1 + 5 = 4

AP : 7 , ___ , 47

first term , a = 7

common difference , d = ?

d = ap - aq / p - q

= a3 - a / 3 - 1

= 47 - 7 / 2

= 40 / 2

d = 20

a2 = a + (n-1) d

= 7 + (2-1) 20

= 7 + 1 × 20

= 7 + 20

a2 = 27

Hope it's helpful .....

Please mark it as Brainliest ..... ❤