Question

the 11th and 21st term of an ap are 16 and 29 respectively, find first term and common difference​

Answer 1

Answer:

d= 1. a= 1

Step-by-step explanation:

a11 = a+(n-1)d

16=a+(16-1)d. .1 eqn

a21=a+(n-1)d

29=a+(29-1)d. 2 eqn

substract 1 and 2

16-29=a+15d-(a+28d)

-13=a+15d-a-28d

-13=-13d

d=1

d value fill in 1 or 2

16=a+15d

16=a+15(1)

16-15=a

a=1

d=1. a=1