80（X+2）=100X

80（X+2）=100X

80x+160=100x
20x=160
x=8

If we know the complex number Z = followed by 3 + I / {1-radical 3I}, then | I |=

z=(√3+i)/(1-√3i)
=(√3+i)(1+√3i)/(1-3i^2)=(√3+√3i^2+4i)/4=i
|z|=1
|i|=1

Solution, a high school mathematics problem solution
In the triangle ABC, the vector AB = (1,2), AC = (- x, 2x) x > 0. If the perimeter of the triangle ABC is 6 times the root 5, what is x?

First, the vector BC = ac-ab = (- x-1,2x-2)
Then the module lengths of the three sides are calculated respectively
|Ab | = radical 5
|AC | = x times root 5
|BC | = (x-1) times root 5
|Ab | + | AC | + | BC | = 6 times root 5
1+X+X-1=6,X=3