Question

If p = −2, q = −1 and r = 3, find the value of 3p²q + 5pq² + 2pqr

Answer 1

3p²q + 5pq² + 2pqr

Substituting p = -2, q = -1 and r = 3 in the given expression:

\[3 \times ( - 2 )^2 \times ( - 1) + 5 \times ( - 2) \times ( - 1 )^2 + 2 \times ( - 2 \times - 1 \times 3)\]
\[ = 3 \times ( - 2 \times - 2) \times ( - 1) + 5 \times ( - 2) \times ( - 1 \times - 1) + 2 \times ( - 2 \times - 1 \times 3)\]
\[ = - 12 - 10 + 12\]
\[ = - 10\]