Answer:
b. x + 1
Step-by-step explanation:
x¹⁶ − x¹⁴ = k (x¹⁵ − x¹⁴)
x¹⁴ (x² − 1) = k x¹⁴ (x − 1)
x² − 1 = k (x − 1)
(x − 1) (x + 1) = k (x − 1)
x + 1 = k
