Question

in AP if a 7 is equal to 39 A3 is equal to 33 find 20th term ​

Answer 1

Answer:

what is common difference and first term

Answer 2

Step-by-step explanation:

Given in the AP

we know

An=a+(n-1)d

so,

A7=a+(7-1)d

A7=a+6d. => 39=a+6d. ......(i)

similarly

A3=a+2d => 33=a+2d ...........(ii)

subtracting eqn ii from i,

6= 4d

=>d=3/2

a =33-2d =>a=30

so,

A20=30+19X3/2

A20 =30+28.5=58.5(ans)