刚刚看到MBA06 got 750,恭喜！但我还是要问TT gwd-6-20

20.

if 2^x+2^x+2^x+2^x=2ⁿ, what is x in terms of n?

it seems to me pretty simple, however, ..............

4*2^x=2^n

so

2+x=n

so

x=n-2