Answer:
78 rounds to 80. So decrease 22% to 1/5. Increase 78 to 80. = 17.16.
I hope this will help you..
Let's say x is longest side, y is shortest side and z is the other side. So we have some equations such that

(by the first sentence)

(by the second sentence)

(by the third sentence)
By the second equation, we have

and if we use it in the first equation, then

. So

Since

, if we use it in the third equation the we have

then

Therefore
Orientation may change, but the measure of its angles will stay the same. A translation does not change the shape of a figure, it only moves its location and direction.<span />
5
8
6 or 7
Just taking a guess
If the sum is negative or if the signs are different and the negative has a biger absoulute value.