Need some help

[alpine dagger]

i as in sqrt(-1)?

Or as a variable

[ivory canyon]

definitely use substitution

but you can also factor out 500 from both sides to make the problem look a bit simpler

x = 1 + i/4

12 = 5x^40

from there try to get identities for powers of x and use substitution for the higher powers

so x^2 = 1 + i/2 - 1/16 = 15/16 + i/2

and then the problem is 12 = 5(x^2)^20

you can always also move the 12 over to the same side as the other terms to get