Answer:
It is necessary to do the same thing to both sides of th equation to perform valid operations because your equation would change otherwise. If you do not do the same action on both sides, your equation will not stay the same as it started. One side could get too large or too small in amount for the other side.
Step-by-step explanation:
Take 2x + 7 = 6 for example. First, you would subtract 7 from both sides. Your new equation is 2x = -1. Then, divide two from both sides. The new equation is
.
If you hadn't subtracted 7 from both sides, the equation wouldn't have stayed the same, and you wouldn't have gotten the correct answer. Your equation would have changed to 2x = 6. Your answer would be x = 3. These two equations are not the same.
This shows that it is necessary to do the same thing to both sides of the equation.
Hope it helps. Good Luck!