in order to solve for x you have to set x by itself, this has an x in both sides of the equation so your first step will be setting the smallest x to the other side, in this case 2x is the smallest x and since it is a positive you have to subtract it(because the only way to get rid of a positive is with a negative) now you will be left with 5x=-35, now your last step to leave x by itself is divide 5 by both sides, why divide because the x is multiplied by 5 and the only way to get rid of a multiplication is with a division... so this gives you a result of x=-7
Hope this helps