How do you evaluate #(2x + 3) ( 4- x )#?

2 Answers
Oct 19, 2017

#-2x^2 + 5x + 12#

Explanation:

#(2x+3) (4-x) = (2x+3)*4 + (2x+3)(-x)#
#= 8x + 12 -2x^2 -3x = 12 +5x - 2x^2#

Oct 19, 2017

#-2x^2+5x+12#

Explanation:

To multiply two binomials, you want to use FOIL (which I'll explain a bit later). The idea is to multiply each term of one binomial with every term in the other binomial.

FOIL stands for First, Outer, Inner, Last.

First: Multiply the first term of each binomial.
#(2x)*(4)=8x#

Outer: Multiply the outer terms.
#(2x)*(-x)=-2x^2#

Inner: Multiply the inner terms.
#(3)*(4)=12#

Last: Multiply the last term of each binomial.
#(3)*(-x)=-3x#

Now, add everything you've got.

#(8x)+(-2x^2)+(12)+(-3x)#

Finally, simplify.

#-2x^2+5x+12#