I know immediately that hippo is wrong**, because the last terms -6 * 8 = -48; not [ 2 * 16 = 32 ]. And there is no reason to factor out a 2. just use an extended version of FOIL to accomplish the job using a (transitive ??) property. dots are where a sign goes:
( a ... b ... c ) * ( d ... e ... f ) = ad..ae..af..bd..be..bf..cd..ce..cf
** in fairness, it was a small mistake, dividing 6 by 2 and getting 2, instead of 3
Answers & Comments
Verified answer
(6x²-2x-6)(8x²+7x+8)
6x²(8x²+7x+8)-2x(8x²+7x+8)-6(8x²+7x+8)
48x^4+42x^3+48x^2-16x^3-14x^2-16x-48x^2-42x-48
4x^4+26x^3-14x^2-58x-48 <===== answer :)
I know immediately that hippo is wrong**, because the last terms -6 * 8 = -48; not [ 2 * 16 = 32 ]. And there is no reason to factor out a 2. just use an extended version of FOIL to accomplish the job using a (transitive ??) property. dots are where a sign goes:
( a ... b ... c ) * ( d ... e ... f ) = ad..ae..af..bd..be..bf..cd..ce..cf
** in fairness, it was a small mistake, dividing 6 by 2 and getting 2, instead of 3
{ when I do that, I blame my bifocals, lol }
Its easier if you take a 2 out of the first bracket to start giving you
2(3x² - x -2)(8x² + 7x +8)= 2(24x^4 + 21x^3 + 24x² - 8x^3 -7x²-8x-16x²-14x -16)
Now if you collect similar terms together you get
2(24x^4 + 13x^3 + x² -20x-16)
Just expand out the brackets.