Finding the domain for this equation

I need help finding the domain for this equation:

x+3/x-4

an explanation would be greatly appreciated, Thanks!

I assume you mean:

(x + 3) / (x - 4)

In which case, you just need to pick out what makes the bottom (denominator) zero:

x - 4 = 0 --> x = 4

So it's all real numbers except x = 4

(that's assuming they wanted you to use the largest subset of the real numbers possible).

It would also be correct to say that the domain was all negative real numbers. The thing I HATE about high school math is that the teachers don't understand functions.

You NEVER EVER ask someone what the domain of a function is. It doesn't make sense to talk about functions without FIRST giving the domain. You cannot call something a function unless you give the domain and range first (that should NEVER be asked of you).

BTW: that was never an equation (no equals sign) you say it's a function or an expression, but NOT an equation.

if you mean x+(3/x)-4 the domain is anything except 0
If you mean x+3/(x-4) (this is probably what you meant) The domain is anything except 4 ie
{x in R : x not = 4}