How do you expand #(x+7)(3x-6)#?

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Answer 1 · 2018-06-19T12:16:35

See a solution process below:

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)(7))(color(blue)(3x) - color(blue)(6))# becomes:

#(color(red)(x) xx color(blue)(3x)) - (color(red)(x) xx color(blue)(6)) + (color(red)(7) xx color(blue)(3x)) - (color(red)(7) xx color(blue)(6))#

#3x^2 - 6x + 21x - 42#

We can now combine like terms:

#3x^2 + (-6 + 21)x - 42#

#3x^2 + 15x - 42#