The goal to solving for the variable (the letter) is to isolate the variable on the lefthand side of the equal sign and the constants (the numbers) on the righthand side. We accomplish this by doing the "opposite" operation to both sides of the equal sign to keep both sides "balanced."
Let's look at the first example, equation 1...
a-5=9...........equation 1, given
a-5+5=9+5.......add 5 to both sides
∴ a=14.........simplify (our solution)
To check our work, substitute the calculated solution
into the original equation...
14-5=9..........substitute the number "14" for the variable "a"
9=9..........true, check√, our solution is correct
always check the solution.
Now apply the above illustrated procedure to the remaining problems. 2 thru 5.
