In multiplying two expressions we have to use distributive property that is (a+b)(c+d) = ac + ad + bc + bd .
So for [tex] (x + 2)(x^2 - 7x + 4) [/tex]
We will get
[tex] (x )(x^2 - 7x + 4) +2(x^2 - 7x + 4) =x^3 -7x^2 +4x +2x^2 -14x +8 = x^3 -5x^2-10x+8 [/tex]
And that's the required result of the product of the given expressions .