Question

the third term of an ap is A -2B,the fifth term is A+5B.find the first term

Answer 1

Ans :-

a3 = a+2d = A-2B ------------1

a5 = a+4d = A + 5B -----------2

On solving 1 and 2,

we get -2d = -7B

So d= 7B / 2

Sub in 1, we get a+ 2(7B/2) = A-2B

a = A-2B-7B = A-9B

First term a = A-9B

Answer 2

Answer:

Explanation:

Gen term=a+(n-1)d

a3=a+2d=A-2B

a5=a+4d=A+5B

From this we get,

A-2B-2d=A+5B-4d

=>2d=7B=a

Solving this we get,

=>7B+7B=A-2B

=>14B=A-2B

=>A=16B

a=first term=7B