You missed an operand in the set of parentheses...if it was (x-9) we have:
5(x-9)-23=42 do multiplication indicated on left side...
5x-45-23=42 sum up like terms on left...
5x-68=42 add 68 to both sides
5x=110 divide both sides by 5
x=22 since this answer isn't in your choices the parentheses must have contained (x+9)...uggh :)
5(x+9)-23=42 perform indicated multiplication on left side...
5x+45-23=42 combine like terms on left side...
5x+22=42 subtract 22 from both sides
5x=20 divide both sides by 5
x=4