What is the value of x in the equation -x

Since, you have not told what the expression -x equals to. So, I am assuming the expression -x is equal to zero. i.e. -x = 0 to make it an equation to determine the value of x.

The value of x is zero i.e. x= 0 in the equation -x = 0.

The graph of the equation  -x = 0 is also attached.

Step-by-step explanation:

As we know that an equation is a mathematical sentence which has two equal sides. These two equal side separated by an '=' sign - often called equal sign.

For example, 3 + 8 = 11 is an example of an equation.

Now, considering the expression

-x

Let us determine the value of x by equaling the expression to zero.

i.e.

-x = 0

so lets solve -x = 0

considering the equation

Therefore, the value of x is zero i.e. x= 0 in the equation -x = 0.

The graph of the equation  -x = 0 is also attached.

5(9+x)=80

Each box contains 9+x pounds, and there are 5 boxes. All 5 boxes together weigh 80 pounds.