Answer:
[tex]57-12x[/tex]
Step-by-step explanation:
In the first part you would distribute the negative
[tex]-(-9-6x) \\-(-9) = --9 = +9 = 9\\-(-6x) = --6x = +6x = 6x[/tex]
So right now you have
[tex]9+6x+6(8-3x)[/tex]
Now you distribute the 6
[tex]6(8) = 6 * 8 = 48\\6(-3x) = 6*-3x = 6* -3 * x = -18x[/tex]
Your equation now looks like
[tex]9+6x+48-18x[/tex]
Combine like terms
[tex]6x-18x = -12x\\9+48 = 57[/tex]
Your answer is
[tex]57-12x[/tex] aka [tex]-12x + 57[/tex]
