Question 1106836
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That's the wrong answer.

If you mean this:

a-4b(a+b)

then we distribute only the -4b:

a-4ba-4bČ   

and since "a" comes before "b" in the alphabet

we write "ba" as "ab" to keep alphabetical order:

a-4ab-4bČ   <--final answer

---------------------------

However if you meant this

(a-4b)(a+b)


then we must first write the second parenthese
beside each of the two terms in the first 
parentheses like this:  

a(a+b)-4b(a+b)

Then we distribute twice, once with the "a"
over (a+b), and then again with the -4b over
the (a+b)

aČ+ab-4ba-4bČ

Now since "ba" is the same as "ab" we write

aČ+ab-4ab-4bČ

Finally since +ab and -4ab are like terms,
we combine the coefficients and get

aČ-3ab-4bČ   <--final answer

Edwin</pre></b></font>