The following equations are equivalent:
2 + x = 5
x + 1 = 4
Negative 5 + x = negative 2
This is because, in each equation, x is the same variable, and it has the same value on both sides of the equation.
In the first equation, x is equal to 3.
In the second equation, x is equal to 3
In the third equation, x is equal to -3
Note that the equation 9 + x = 6 and x + (negative 4) = 7 are not equivalent as these equations have different values for x.