Question

For an ap show that a p + 80 + 2 q is equal to 280 + q

Answer 1

 LHS = 

ap + ap+2q =

{a+(p-1)d} + {a +(p+2q-1)d}

a + dp -d + a +dp +2dq-d

2a +2pd -2d +2dq 

=2(a+dp-d+dq)

 

RHS

{a + (p+q-1)d}2

(a+dp+dq-d)2

LHS= RHS

HENCE PROVED