Expert: Josh - 6/16/2009

Question
-6x-7(4+3x)

Thanks, Josh!

Answer
Gita,

As a general rule, always simplify any expression inside the parenthesis first if at all possible. Then, do all the multiplications and divisions, from left to right; followed by additions and subtractions.

Here, we note that -6x-7(4+3x) is a shorthand way of writing -6x-7*(4+3x). We deal with the expansion of 7(4+3x) first, since multiplication takes precedance over addition and subtraction. We associate 7 with (4+3x) and multiply them together. This gives 7*4+7*3x = 28 +21x.

The whole thing "-6x-7(4+3x)" then becomes
-6x -(28+21x)   (we have replaced 7(4+3x) with 28+21x)
= -6x -28 -21x  (note)
= -6x-21x -28
=-27x -28

note: in this line, we gather the two terms that contain "x" and do the required subtraction.