If p+q+r=9,pq+qr+rq=26,find the value of p×p×p+q×q×q+r×r×r-3pqr
Answers
Answered by
8
Hey buddy B-)
here,
=> p + q + r = 9
squaring b/s, we get
=>(p + q + r)^2 = 9^2
=>p^2 + q^2 + r^2 + pq +qr + rp = 81
=>p^2 + q^2 + r^2 + 26 = 81
( pq + qr + rp = 26 given)
=>p^2 + q^2 + r^2 = 81 - 26 = 55
now, using
=> p3 +q3 +r3 3pqr = (p+q+r)(p^2+q^2+r^2 - pq - qr - rp)
=> 9(55 - 26)
=> 9x 29 = 261
HOPE THIS HELPS (^o^)
here,
=> p + q + r = 9
squaring b/s, we get
=>(p + q + r)^2 = 9^2
=>p^2 + q^2 + r^2 + pq +qr + rp = 81
=>p^2 + q^2 + r^2 + 26 = 81
( pq + qr + rp = 26 given)
=>p^2 + q^2 + r^2 = 81 - 26 = 55
now, using
=> p3 +q3 +r3 3pqr = (p+q+r)(p^2+q^2+r^2 - pq - qr - rp)
=> 9(55 - 26)
=> 9x 29 = 261
HOPE THIS HELPS (^o^)
Similar questions