1 → - 13 , 2 → 31, 3 → 22, 4 → 19
substitute the given values for x, y and z into the expressions
1. xy - z = (2 × - 5) - 3 = - 10 - 3 = - 13
2. 6(z - x) + y² = 6(3 - 2) + (- 5)² = (6 × 1) + 25 = 6 + 25 = 31
3. 2x - 3y + z = (2 × 2) - (3 × - 5) + 3 = 4 - (- 15) + 3 = 4 + 15 + 3 = 22
4.[tex]\frac{12z + 20x}{4}[/tex] = [tex]\frac{12.3 + 20.2}{4}[/tex] = [tex]\frac{36 + 40}{4}[/tex] = [tex]\frac{76}{4}[/tex] = 19
