x - (4 - x)
When there is an expression parentheses, and there is no number just before
the parentheses, just a sign, then put a "1" befween the sign and the "(",
like this:
x - 1(4 - x)
Now, remove the parentheses by using the distributive principle. That is,
multiply the -1 outside the parentheses by the 4 and also by the -x inside the
parentheses:
x - 1·4 + x
(the + before the x is because -1 times -x is +x.
Replace 1·4 with 4
x - 4 + x
Now put 1's before the x's
1x - 4 + 1x
Combine the first term, 1x, with the third term,
which is also 1x, and get 2x.
2x - 4
Edwin
AnlytcPhil@aol.com
