With that out of the way, we can move onto the problem at hand! 19 = (h/3) - 8
When trying to solve for a variable you must first get the variables expression alone (In this case the expression (h/3)). To do that in this case we must get rid of a 8 which is being subtracted from (h/3). So the inverse operation of subtraction is addition, thus we add 8 on both sides! Like a so...:
19 + 8 = (h/3) - 8 + 8
The two 8s on the right cancel out, because -8 + 8 = 0.
19 + 8 = (h/3)
Simplify the right side by adding together 19 and 8.
27 = (h/3)
Now we need to get h alone by removing the 3 which it is being divided by. So we use the inverse operation of division which is multiplication.
27 * 3 = (h/3) * 3
The 3s on the right cancel out, because 1/3 * 3 = 1.
