Respuesta :

krystal2022
the answer is u=x2 to the question
abidemiokin

The Substitution that should be used is u = x²

Quadratic equations

Given the quartic polynomial expressed as:

  • 4x⁴ – 21x² + 20 = 0

We need to find a substitute that will reduce the quaryic equation to a quadratic equation.

To do that, we can rewrite the equation as;

  • 4(x²)² - 21x² + 20 = 0

Let P = x² to have:

4P² - 21P + 20 = 0

Since this is a quadratic equation, hence the Substitution that should be used is u = x²

Learn more on quadratic equation here: https://brainly.com/question/1214333