Start with an expression for the left-hand side and choose any negative number, then calculate the expression's value when x equals that negative number.
Example Solution: 2x+9=x+4
Practice makes perfect
We are going to write an equation that has a negative number as the solution and contains the variable x on both sides. We can start off with any linear expression for the left-hand side.
2x+9
Now let's choose that our solution will be x=-5. By substituting -5 for x into the equation, we can determine what the expression equals.
This means that the expression 2x+9 needs to be equal to -1.
2x+9=-1
Let's find another expression that equals -1 when x=-5. The simplest way to do this is by writing an expression where a number n added to x equals -1.
x+n=-1
To find n, we should substitute -5 for x.
Therefore, we found another expression that equals -1 when x=-5.
x+4
Since both expressions equal -1 when x=-5, we can set them equal to one another. This will be our equation.
2x+9= x+4
Let's check our solution just to make sure. To do this we will solve the equation using the Subtraction Property of Equality.
