X4 – 17x2 + 16 = 0 rewrite the equation in terms of u

You probably are interested in expressing the given equation as a quadratic equation in u, as it will make it easy to find the solutions.

Let u = x²
So,
u² = x⁴

So, the given equation can be written as:

u² - 17u + 16 = 0

Now the equation is quadratic in u and the solutions can be calculated using quadratic formula or factorization.

The correct answer is -4