How do you multiply #(x + 5) ( 4x ^ { 2} - 3)#?

2 Answers
Nov 14, 2017

See a solution process below:

Explanation:

To multiply these two terms you multiply each individual term in the left parenthesis by each individual term in the right parenthesis.

#(color(red)(x) + color(red)(5))(color(blue)(4x^2) - color(blue)(3))# becomes:

#(color(red)(x) xx color(blue)(4x^2)) - (color(red)(x) xx color(blue)(3)) + (color(red)(5) xx color(blue)(4x^2)) - (color(red)(5) xx color(blue)(3))#

#4x^3 - 3x + 20x^2 - 15#

We can now write this in standard form:

#4x^3 + 20x^2 - 3x - 15#

Nov 14, 2017

#color(green)(4x^3+20x^2-3x-15#

Explanation:

#(x+5)(4x^2-3)#

#color(white)(aaaaaaaaaaaaaa)##x+5#
#color(white)(aaaaaaaaaaa)## xx underline(4x^2-3)#
#color(white)(aaaaaaaaaaaaa)##4x^3+20x^2#
#color(white)(aaaaaaaaaaaaaaaaaaaaaaa)##-3x-15#
#color(white)(aaaaaaaaaaaaa)##overline(4x^3+20x^2-3x-15)#

#color(white)(aaaaaaaaaaaaa)##color(green)(4x^3+20x^2-3x-15#