i is the variable here so you need to isolate it.
We see a number multiplied to a ( ) so let's use the distributive property first!
2*1-2*3i-2i=18
Now combine liked terms
2-8i=18
We should subtract 2 from both sides of the equation to isolate the term containing i
2-8i-2=18-2
-8i=16
Now we divide -8 from both sides to isolate i completely by itself.
-8i/-8=16/-8
i=-2
Now check our work!
2(1-3*-2)-2*-2=?=18
2(1+6)+4=?=18
14+4=18
Therefore i=-2 is correct!