If two expressions are equal to each other, and you add the same value to both sides of the equation, the equation will remain equal. Then, in the first case, we can add -7 to both sides and get

Similarly, in the second case, we can add -14 to both side and get

We can also divide both sides by the same quantity. In the first case, we can divide by 2 and ger

in the second case, we can divide by 4 and get

Finally, in the first case, we can add -1 to both side and get

Similarly, in the second case, we can add -2 in both sides and get

Then, in sumarry, you can add, substract, multiply or divide by the same number in both sides in order to remain the equallity of the given equation