Hi there!
Great question! :D
Since there is a variable right next to the -4, we know it means to multiply. But, we will do the opposite operation - Division!
Here's how it works:
Divide both sides by -4. Why both? Because what you do to one side, you have to treat the other equally (or the other will feel slighted!).
[tex] \frac{-4x}{4} = \frac{-36}{4} [/tex]
[tex]x = 9[/tex]
Now, we can see simply that [tex]x = 9[/tex]
Here's a question some people ask when solving for x -
* Why is that the answer? How do you know?
Because you can always substitute the x for the 9. Earlier we mentioned that a variable next to a number means to multiply.
So, [tex]-4 * 9 = -36[/tex] WE WERE RIGHT!!!
Another question:
*Negative 36? Why would the answer not be -9?
We can eliminate 2 answers already - The negative ones. Negative + negative = positive, and our 36 here is negative, and the 9 is positive, and so a formula you want to keep in mind is:
negative + positive = negative.
positive + positive = negative.
negative + negative = positive.
Hope this helps! :D
