Can someone tell me if this is correct: Find the value of the polynomial -x^2-3x-1 when x=-4
-1(-4)^2+3(-4)-1
-1(8)+(12)-1
-8-12+1
-20+1
=19
Is this correct??
for x= -4
x^2 is not 8
x^2=(-4)^2=4^2=16
To find the value of the polynomial -x^2-3x-1 when x=-4, you can substitute the value of x into the polynomial expression and evaluate it.
Starting with the given polynomial expression: -x^2-3x-1
When x=-4, substitute -4 for every x in the expression:
-(-4)^2-3(-4)-1
Next, follow the order of operations (PEMDAS) to simplify:
-(-4)^2 gives -16 (since raising a negative number to an even power makes it positive: (-4)^2 = 16)
-3(-4) gives +12 (multiplying a negative number by a negative number gives a positive result)
Now you have:
-16 + 12 - 1
Simplify further:
-4 - 1 = -4
So, the value of the polynomial -x^2-3x-1 when x=-4 is -4.
To answer your question, no, your answer of 19 is not correct. The correct answer is -4.