How do you simplify #3x ( x - 9) + 7( x - 9)#?

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Answer 1 · 2017-09-30T12:02:36

See a solution process below:

First, expand the terms in parenthesis by multiplying each term within the parenthesis by the term outside the parethesis:

#color(red)(3x)(x - 9) + color(blue)(7)(x - 9)#

#(color(red)(3x) xx x) - (color(red)(3x) xx 9) + (color(blue)(7) xx x) - (color(blue)(7) xx 9)#

#3x^2 - 27x + 7x - 63#

Now, combine like terms:

#3x^2 + (-27 + 7)x - 63#

#3x^2 + (-20)x - 63#

#3x^2 - 20x - 63#

Depending on the simplified form being requested this expression can also be factored as:

#(3x + 7)(x - 9)#