9-2x+35
first you want to get rid of the number. so you subtract 9 on both sides. Think of this as a balance scale, what you do on one side must be done on the other.
9-2x+35
-9 -9
-2x= 26
you always want to do the opposite, so since this was positive 9 you subtract so the 9 is gone.
-2x=26
/-2 /-2
you divide each side by -2 and you get
x=-13
since a negative divided by a positive is a negative