Question

If x = 1, y = 2 and z = 5, find the value of 2x² y − 5yz + xy²

Answer 1

\[2 x^2 y - 5yz + {xy}^2\]

Substituting x = 1, y = 2 and z = 5 in the given expression:
\[2 \times (1 )^2 \times 2 - 5 \times 2 \times 5 + 1 \times (2 )^2 = 4 - 50 + 4\]
\[ = - 42\]