Respuesta :

Answer: -b - 9

Step-by-step explanation:

First, since the a cancel eachother out we are left with (4-b) + (-6-7)

Second, you want to add the -6 and -7 to get -13, so (4-b) - 13

Finally, add the 4 to the negative 13 to get (-b - 9)

Hope this helps.