This is what I got--
24+12-21-30 = -15
Therefore, the coefficient would be -15.
Hope this helped!
The two expressions are to be MULTIPLIED by each other, not ADDED, which is what you got !!!
Qwerty would you like me to answer on the original question? I guess I could
I can try again.... It's just factoring.
This is the correct answer:
Expand the following:
(24 x^4 + 6 x^3 + 4 x^2 - 7 x - 5) * (6 x^3 + 3 x^2 + 3 x + 4)
=144 x^7 + 108 x^6 + 114 x^5 + 84 x^4 - 15 x^3 - 20 x^2 - 43 x - 20
I just checked with an online polynomial expander, and it appears my answer of -15 was correct. How exactly did you arrive at your answer of -43?
EDIT: I think you arrived at the right polynomial. It's just asking for the x^3 term, not the x term :P
jfan17 your answer was -15, too? So was mine! Check the top answer.....
What is the coefficient of x^3 when 24x^4 + 6x^3 + 4x^2-7x - 5 is multiplied by 6x^3 + 3x^2 + 3x + 4 and the like terms are combined?
( 24x^4 + 6x^3 + 4x^2 - 7x - 5) * ( 6x^3 + 3x^2 + 3x + 4)
The coefficient on x^3 will be found as
6x^3 * 4 + 4x^2 * 3x - 7x* 3x^2 -5*6x^3 =
[ 6* 4 + 4*3 - 7*3 - 5*6 ] x^3 =
[24 + 12 - 21 - 30 ] x^3 =