Final answer:
The value of the expression -2y+z at x=2, y=5, and z=-1 is -11.
Step-by-step explanation:
To evaluate the expression -2y+z at x=2, y=5, and z=-1, we substitute the given values into the expression:
= -2(5)+(-1)
= -10 - 1
= -11
So, the value of the expression is -11.