Question
If p = 33 - q - r and pq + r(q + p) = 260, then find
the value of (p² + q² + r²).Solution
We have, p = 33 - q - r So, p + q + r = 33 And, pq + r(q + p) = 260 Or, pq + qr + pr = 260 Using, (p + q + r)² = p² + q² + r² + 2(pq + qr + pr) So, 33² = (p² + q² + r²) + 2 × 260 Or, 1089 = (p² + q² + r²) + 520 Or, p² + q² + r² = 1089 - 520 Or, p² + q² + r² = 569
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