Evaluate:

xz (x² + y²) for x = 2, y = 1 and z = 1.

xz (x² + y²)

= x⁽²⁺¹⁾z + xzy²

= x³z + xzy²

For x = 2, y = 1 and z = 1

2³ x 1 + 2 x 1 x 1²

= 8 x 1 + 2 x 1 x 1

= 8 + 2

= 10

Hence, for x = 2, y = 1 and z = 1, the value of xz (x² + y²) is 10.