Question

If p, q,r are in AP, then p3 +r3 - 8 q3 is equal to​

Answer 1

Answer:-6prq

Step-by-step explanation:[q-p]=[r-q]

so q = p+r/2

so p+r=2q ----------1

now

p+3+r+3-8q+3 substituting for q we get

= p+3+r+3-8[p+r/2]+3

=p+3+r+3-8[p+r]+3/8

=p+3+r+3-[p+r]+3

=p+3+r+3-[p+3+r+3pr[p+r]]

=p+3+r+3-p+3-r+3-3pr[p+r]

=-3pr[p+r]

=-3pr[2q] from 1

=-6prq