Question 5158
get all the like terms on one side, so we will move the whole of the 5x from the righthand side. How? by taking it away. But what you do to one side, you must also do to the other, so we get: 


2x-5x=5x-12-5x 
-3x = -12


Now we wish to find x=.. or more correctly, what 1x equals. We have -3x, so we need to convert the -3 to a 1 (without "touching" the x). How? by dividing by -3


-3x/-3 = -12/-3


x = +4 since a minus and a minus is +


jon.