How do you simplify #1/3(15a+9b)-1/7(28b-84a)#?

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Answer 1 · 2017-01-24T14:02:27

See the entire simplification process below

First, expand the terms in parenthesis by multiplying the by the terms outside their respective parenthesis:

#color(red)(1/3)(15a + 9b) - color(blue)(1/7)(28b - 84a) ->#

#(color(red)(1/3) xx 15a) + (color(red)(1/3) xx 9b) - (color(blue)(1/7) xx 28b) + (color(blue)(1/7) xx 84a) ->#

#5a + 3b - 4b + 12a#

Next, group like terms:

#5a + 12a + 3b - 4b#

Now. combine like terms:

#(5 + 12)a + (3 - 4)b#

#17a - 1b#

#17a - b#