Thread: 12 = 11x - 14x

Any hints on where I went wrong?






When checking the solution in the original equation, I got the false answer of:

Originally Posted by Euclid Alexandria

Any hints on where I went wrong?






When checking the solution in the original equation, I got the false answer of:

minus times minus is plus.

so -14(-4)=-(-56)=+56

RonL

Originally Posted by Euclid Alexandria

Any hints on where I went wrong?






When checking the solution in the original equation, I got the false answer of:

Also, even though the step that it came from was in error, -44 - 56 = -100.

-Dan

The reason I became confused is, in simplifying equations like



I thought we were supposed to treat the negative sign in the middle as a subtraction sign. I thought we were to solve the two multiplication problems first, then subtract. I could swear I've seen situations that were similar enough in that vein, to confuse me about this situation. If that's the case, I need to learn to tell the difference.

Thankfully, at least the variable was correct this time, so I'm improving.

Originally Posted by Euclid Alexandria

The reason I became confused is, in simplifying equations like



I thought we were supposed to treat the negative sign in the middle as a subtraction sign. I thought we were to solve the two multiplication problems first, then subtract. I could swear I've seen situations that were similar enough in that vein, to confuse me about this situation. If that's the case, I need to learn to tell the difference.

Thankfully, at least the variable was correct this time, so I'm improving.

If your teacher will allow it, this might help:
When I was learning this my teacher always insisted that we write expressions like as . That way you never have to worry about whether or not you are adding or subtracting...you are ALWAYS adding.

Hope it helps!
-Dan

I was doing this for a while, but have been trying to wean myself off of it. I still use it for larger problems, but might continue sticking with it for a while in every case.

Btw, I finally noticed my error while resolving that equation, so disregard my previous post!

Originally Posted by Euclid Alexandria

I was doing this for a while, but have been trying to wean myself off of it. I still use it for larger problems, but might continue sticking with it for a while in every case.

Btw, I finally noticed my error while resolving that equation, so disregard my previous post!

I did that myself for a while. Believe it or not, I've come back to doing it again because the process makes it just SO much easier to find mistakes!

-Dan