Question

Solve –4x = –36.
–9
–32
9
–40

Answer 1

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!).


`(-4x)/(4) = (-36)/(4)`


`x = 9`

Now, we can see simply that
`x = 9`

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,
`-4 * 9 = -36` 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

Answer 2

First you start out with your equation:
-4x = -36

Using reverse operations, divide both sides by -4. Since you're dividing a negative by a negative, you get a positive answer.

x = 9