Respuesta :

Answer:

u = -3

Step-by-step explanation:

[Given]

7 = 10 + u

[Subtract 10 from both sides of the equation]

-3 = u

[Reflexive Property]

u = -3

Have a nice day!

     I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly.

- Heather