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??
2007-10-05 16:24:22 · 22 answers · asked by tricey7578 2 in Science & Mathematics ➔ Mathematics
-1(-4)^2+3(-4)-1
-1(16)-12-1
-16-12-1
=-29
2007-10-05 16:32:32 · answer #1 · answered by Wa Lao 6 · 1⤊ 2⤋
For those who answered -5 are correct. For those who answered 27 are wrong, since -x^2 should be -1(-4)^2=-1(16)=-16, hence, -16+12-1=-5. And those who answered -29 are also wrong since -3(-4) should be +12 not -12 .
2007-10-06 04:05:20 · answer #2 · answered by casey 1 · 0⤊ 0⤋
Wes said it; too many answers for a simple problem
Here is how to do it:
-x^2-3x-1, x=-4
-(-4)^2-3(-4)-1
-16+12-1 = -5
2007-10-05 16:51:07 · answer #3 · answered by james w 5 · 0⤊ 0⤋
No, it is not correct
-x^2-3x-1
-1(-4)^2 -3(-4) -1
-1(16) +12 -1
-16+12-1
-5
2007-10-05 16:37:12 · answer #4 · answered by Grampedo 7 · 0⤊ 0⤋
Your flaw is that you messed up the signs and didn't square correctly
EDIT: you messed up the signs so bad I got messed up..
It should be
-1(-4)^2-3(-4)-1 < MINUS 3
-1(16)+(12)-1 < 16 not 8
-16+12-1 < -1 not +1
-4-1 <- same as above
=-5
2007-10-05 16:33:21 · answer #5 · answered by sirfastolfe 2 · 0⤊ 1⤋
no..
-(-4)^2-3(-4)-1
= -16+12-1
= -4-1
= -5
2007-10-05 16:32:06 · answer #6 · answered by mhymhymhymhymhymhymhy 2 · 1⤊ 1⤋
no
-4^2 is not 8
2007-10-05 16:29:23 · answer #7 · answered by Jay 4 · 0⤊ 1⤋
-(-4)^2-3(-4)-1
-16+12-1
-4-1
-5
2007-10-05 17:19:02 · answer #8 · answered by sportgrl 2 · 0⤊ 0⤋
No, the square root of 4 is 16, not 8. Also the negative on the x value in the squared term must be carried through before you square it The final answer is 27.
2007-10-05 16:31:35 · answer #9 · answered by The Mighty Quinn 2 · 1⤊ 0⤋
I got 27 am i reading your question correctly
negative x squared minus 3x minus one
16 - (-12) - 1
16 + 12 -1 = 27
2007-10-05 20:02:47 · answer #10 · answered by TuesdayStar 6 · 0⤊ 0⤋