Final answer:
To evaluate the polynomial x²-5x+8 for x=-2, we substitute -2 into the polynomial to get 22.
Step-by-step explanation:
The student asked to evaluate the polynomial for x=-2 given by x²-5x+8. To do this, we substitute -2 for x in the polynomial and simplify:
(-2)² - 5(-2) + 8
= 4 + 10 + 8
= 22
This computation shows that when x is -2, the value of the polynomial is 22. This process involves basic algebra and the evaluation of a quadratic expression, which is a fundamental concept in high school mathematics.