Question 737121: (a)(b)+(-a)(b)+(b)(-a)-(a)(b)-(-a)(-b)
How do I solve this or what is the answer?
Answer by josgarithmetic(39620)   (Show Source):
You can put this solution on YOUR website!  is another way of expressing  .
A basic law of real numbers is  .
For two real numbers a and b, a-b means the same thing as a+ (-b).
Review those facts for a few minutes and try.... understand them.
------------------------------------------------------
 , can you see how?
= , but do you know why I show it this way?
=.
= , Excuse me for skipping a step or two.
post-note: There are a couple of ways to go from the step just before the "=." line. The more pathways are shown, the more confusing a solution can be for a student. What may be best if a step is missing is for the student to try to fill in any missing steps. Knowing exactly which steps a student needs and which would be distracting is often not possible. Direct interaction is a better situation sometimes than sending and reading text & symbols messages.
One suggestion for the step at the "=." line is to use the additive inverse concept, like for some number c, we can be assured of c+(-c)=0. The number, c, may stand for any real number, like r, or uw, or xwp, or ab...
|
|
|
