Respuesta :
Answer: -77
Step-by-step explanation:
Let the unknown number be x.
We have been asked to find the unknown x.
It is given that when the unknown x is added to 77, the sum will be zero. Thus the mathematical representation will be:
[tex]77+x=0[/tex]
Taking the unknown to one side of the equation ad solving:
[tex]x=0-77[/tex]
[tex]x=-77[/tex]
Thus the required number is -77.
