Question

{ [(a+2)×2+2]×2+2}×2+2=30

Answer 1

{ [(a+2)×2+2]×2+2}×2+2=30
{ [(a+2)×2+2]×2+2}×2=28
[ (2a+4+2)×2+2]×2=28
[(2a+6)x2+2]x2=28
(4a+12+2)x2=28
(4a+14)x2=28
8a+28=28
8a=0
a=0