The unknown number is x .
An equation to find the value of x :-
[tex]x + 5 = - 4[/tex]
Let us solve this equation :-
[tex]x + 5 = - 4[/tex]
[tex]x = - 4 - 5[/tex]
[tex]x = - 9[/tex]
The value of x is -9 . Let us place -9 in the place of x , to check whether or not we have found out the correct value of x .
So :-
[tex] - 9 + 5 = - 4[/tex]
[tex] - 4 = - 4[/tex]
[tex]LHS = RHS [/tex]
As the left hand side of the equation is equivalent to the right hand side of the equation, we can conclude that we have found out the correct value of x .
Therefore , -9 + 5 = -4 and ( x = -9 ) .
