Answer:
4y^2 - 21y + 20 = 0
Step-by-step explanation:
As (4x^4 - 21x^2 + 20=0) being a biquadratic equation, meaning it is a 4-degree equation without the terms of degree 1 and 3.
To solve this particular case you only need to replace the variables of degree 4 and 2 for a new variable of degree 2 and 1 and solve it as regular quadratic equation and then undo the change.
* Using a new variable we can rewrite the equation:
Let y be the new variable;
y= x^2, then y^2= x^4
Then we have;
4y^2- 21y+20=0
Solve for y and then find X which will be the roots for the biquadratic equation.
