Answers

2014-03-31T10:28:03+05:30
P+2q=8 
Taking cube both the sides.
 p^{3} +8 q^{3} +3pq(p+q)=512
Simply putting the formula⇒ (a+B)^{3} =a^3+b^3+3ab(a+b)
then putting value pq=6 in the above equation. we get.
p^3+8q^3+18(p+q)=512
Now take 18(p+q) in the right
p^3+8q^3=512-18(p+q)
Now take the equation p+2q=8
⇒p+q+q=8
⇒p+q=8-q
now taking the value of p+q and putting in the above generated equation we get
p^3+8q^3=512-144(q)
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