Question

Multiply (x – 4)(x2 + 6x – 5).

Answer 1

(x⋅x2+x⋅6x+x⋅−5−4⋅x2−4⋅6x−4⋅−5) Multiply x by x2 to get x3. (x3+x⋅6x+x⋅−5−4⋅x2−4⋅6x−4⋅−5) Multiply x by 6x to get 6x2. (x3+6x2+x⋅−5−4⋅x2−4⋅6x−4⋅−5) Multiply x by −5 to get −5x. (x3+6x2−5x−4⋅x2−4⋅6x−4⋅−5) Multiply −4 by x2 to get −4x2. (x3+6x2−5x−4x2−4⋅6x−4⋅−5) Multiply −4 by 6x to get −24x. (x3+6x2−5x−4x2−24x−4⋅−5) Multiply −4 by −5 to get 20. (x3+6x2−5x−4x2−24x+20) Since 6x2 and −4x2 are like terms, add −4x2 to 6x2 to get 2x2. (x3+2x2−5x−24x+20) Since −5x and −24x are like terms, subtract 24x from −5x to get −29x. (x3+2x2−29x+20) (x3+2x2−29x+20) Remove the parentheses around the expression x3+2x2−29x+20.

MEH MEH!

Answer 2

(x – 4)(x2 + 6x – 5)
First multiply the 1st term in the left factor by each in the right term:
x3 + 6x2 - 5x
Secondly, multiply the 2nd term in the left factor by each on the right,remembering to carry the (-) sign: -4x2 - 24x + 20
Third, add all like terms:
x3 + 2x2 - 29x + 20