You can actually do it either way, you could distribute first and then combine, you would get the same answer. I guess it just depends on what you find easier. Here is how to solve it both ways:
Combining First:
8(5x+9x+6)=160
8(14x+6)=160
112x+48=160
112x=112
x=1
NOT Combining First:
8(5x+9x+6)=160
40x+72x+48=160
112x+48=160
112x=112
x=1
so, you would get the same answer both ways, it is of personal preference what you do first.
