Question 729598: what does -x+1x equal?
I am trying to solve an equation with this in it....just trying to combine like terms thats all
Answer by KMST(5328)   (Show Source):
You can put this solution on YOUR website! 
We do not usually take the trouble to write the 1 and -1 in front of x as visible coefficients.
You could think of it as
Maybe you could just write
 or even shorter as
The question is how much writing does your teacher expect.
Are you expected to write more baby steps that seems obvious to me and your teacher just to show that you understand what you are doing?
Or would the extra steps just seem ridiculous and annoying to your teacher?
If you had more than a couple of weeks of algebra classes, I would not want to see extra steps.
MY UNDERSTANDING OF ALGEBRA:
Subtraction does not really exist. It is just a reflection of addition, just like the trees you see inside the water on a still pond are just the reflection of trees on the ground next to the pond.
A negative number means just go in the other direction.
5-3 is really 5 + (-3) , which could mean go miles North and them go 3 miles South.
Each variable has a coefficient (a number in front of the variable) even if you do not see one.
x-3x means really 1x + (-3)x, which could mean 1 mile North, then 3 miles South, or one small step North, then 3 small steps South, or deposit one dollar in the bank account, then withdraw 3 dollars. It does not matter what x means, I can add up all the x together.
I do not write more than needed, it just write x-3x=-2x, although I understand that x is 1 times x, -3x is (-3) times x, and they are added so I get (-2) times x.
If you ever see a minus sign in front of a parenthesis, as in
2(x-5)-(x+2) try to see an invisible 1.
It is really 2(x + (-5)) + (-1)(x + 2)= 2x + 2(-5) + (-1)x + (-1)2 = 2x + (-10) + (-1)x + (-2)
The result is 2x + (-10) + (-1)x + (-2), which I write as 2x-10-x-2 .
Next I collect like terms, understanding that what I am doing is rearranging the pieces I am adding and that in baby steps is
2x + (-10) + (-1)x + (-2) = (2x + (-1)x) + ((-10) + (-2)) = (2 + (-1))x + (-12) = 1x + (-12)
I write that final result as just x-12.
I write the whole calculation as
2(x-5)-(x+2) = 2x-10-x-2 = x-12 ,
but I understand that I am working with adding and multiplying positive and negative numbers, some of which are multiplied times x, and since no one has given me a value for x, I have to keep the x stuff separated from the stuff that does not have x (as if it were in separate accounts).
|
|
|
