How do you prove 2x powk plus 4x powk minus 1 equals x powk plus 1?

Answer 1

if you mean: 2x^k + 4x^k -1 = x^k +1

6x^k - x^k = 1 + 1

5x^k = 2

x^k = 2/5 cannot be solved further without more info.

with 2 variables you must have 2 equations to solve further.