# simplifying expressions( using CLT) combine like terms

• Dec 30th 2008, 02:00 PM
honorstudent
simplifying expressions( using CLT) combine like terms
examples: 2+7x+1-7x

9r+6-7
2x+x
8m-6m
-7x-7x
-8+5m=1=9m

HELP!!!
• Dec 30th 2008, 07:13 PM
Aryth
The method for these really aren't that hard, let's take one of your examples:

\$\displaystyle 2 + 7x + 1 - 7x\$

1. Split up all like terms

We can see that 2 and 1 are just regular numbers and that 7x and -7x have an x in common, so we will split them up that way, I like to use parentheses to avoid confusion:

\$\displaystyle (2 + 1) + (7x - 7x)\$

2. Solve the parentheses 1 by 1.

We can see that 2 + 1 is three, but the 7x - 7x is tricky. For a moment, let's pretend that there is not an x there, we would then have:

\$\displaystyle 7 - 7\$

This is obviously 0.

\$\displaystyle 7 - 7 = 0\$

Now, let's put the x back in, this time we multiply everything by x, even the zero, since they are like terms:

\$\displaystyle 7x - 7x = 0x = 0\$ (Zero times anything is zero)

And there you have it, we just put that where we put the (7x - 7x) in the problem:

\$\displaystyle 3 + 0 = 3\$

Hope this helps.