Grade 10Algebra
if sum of first p terms of a.p series is q and sum of first q series is p then what is sum of first (p+q) terms
2 Answers
Nishant Vora
Dear student,
Lets assume
First term = a
and common difference = d
So , a + (p-1)d = q ….….…...(1)
and a + (q-1)d = p ….….…...(2)
From these 2 eqn solve for a and d
and put in this equantion
S(p+q)= a + (p+q-1)d
hence u will get ans
Lets assume
First term = a
and common difference = d
So , a + (p-1)d = q ….….…...(1)
and a + (q-1)d = p ….….…...(2)
From these 2 eqn solve for a and d
and put in this equantion
S(p+q)= a + (p+q-1)d
hence u will get ans
mycroft holmes
The “expert’s “ answer is incorrect.
Solution is given below:
The sum of first n terms AP is of the form an2+bn for some constants a,b
We are given ap2+bp = q
aq2+bq = p
Subtracting, and dividing by (p-q) on both sides, you get
a(p+q)+b =-1
Now multiplying by (p+q) we have a(p+q)2+b(p+q) = -(p+q)
i.e.S(p+q) = -(p+q).
Other Related Questions on algebra
How do you write “the product of 18 and q” as an algebraic expression?
How do you write “the product of 18 and q” as an algebraic expression?
algebra
Last Activity: 2 Years ago