Question 1009479

remember: 
The Order of Operations: PEMDAS
-Do things in Parentheses First.
-Exponents (Powers, Roots) before Multiply, Divide, Add or Subtract.
-Multiply or Divide before you Add or Subtract.
-Otherwise just go left to right.

{{{-9+(2-x)+8x}}}....you need first to eliminate parentheses; if we have plus sign in front of parentheses, just disregard them, nothing will change  

{{{-9+2-x+8x}}} ....now combine like terms

{{{(2-9)+(8x-x)}}}....if you need to subtract greater number from smaller number, just subtract smaller from greater number and put minus sign in front of difference:
so, {{{2-9}}} is same as {{{-(9-2)=-7}}}

{{{-7+7x}}}...you can swap the places

{{{7x-7}}}