what substitution should be used to rewrite $4x^{4}-21x^{2}+20 = 0$ as a quadratic equation?\n$u =…
what substitution should be used to rewrite $4x^{4}-21x^{2}+20 = 0$ as a quadratic equation?\n$u = x^{2}$\n$u = 2x^{2}$\n$u = x^{4}$\n$u = 4x^{4}$
Answer
Answer:
A. $u = x^{2}$
Explanation:
Step1: Analyze the given equation
The given equation is $4x^{4}-21x^{2}+20 = 0$. We know that $x^{4}=(x^{2})^{2}$.
Step2: Make the substitution
Let $u = x^{2}$. Then the equation $4x^{4}-21x^{2}+20 = 0$ becomes $4u^{2}-21u + 20=0$, which is a quadratic - equation in terms of $u$.