Evaluate each polynomial for the given value of the variable.
–x2-5x+6; x= -3
2x2-4x-1; x= 5
- (-3)^2 - 5 (-3) + 6
- 9 + 15 + 6
21 - 9
12
your turn
3x2plus 2x 4x2
To evaluate each polynomial for the given value of the variable, you need to substitute the value of the variable into the polynomial and simplify the expression.
1) For the polynomial -x^2 - 5x + 6, with x = -3:
Replace each occurrence of x in the polynomial with -3:
-(-3)^2 - 5(-3) + 6
Simplify the expression:
-9 + 15 + 6
Combine like terms:
15 - 9 + 6
Simplify further:
6 + 6
Final answer: 12
Therefore, when x = -3, the value of the polynomial -x^2 - 5x + 6 is 12.
2) For the polynomial 2x^2 - 4x - 1, with x = 5:
Replace each occurrence of x in the polynomial with 5:
2(5)^2 - 4(5) - 1
Simplify the expression:
2(25) - 20 - 1
Multiply first:
50 - 20 - 1
Combine like terms:
50 - 20 - 1
Simplify further:
30 - 1
Final answer: 29
Therefore, when x = 5, the value of the polynomial 2x^2 - 4x - 1 is 29.