Question

Solve the equation x4 - 10x² + 25 = 0.​

Answer 1

X^4 - 10x^2 + 25 = 0

( x^2 - 5 )^2 = 0
( because a^2 - 2ab + b^2 = ( a-b)^2 then x^4 - 10 x^2 + 25 = 0 equals (x^2 - 5 )^2 )

√(x^2 -5 )^2 = √0

X^2 - 5 = 0

X^2 = 5

√x^2 = √5

X = - √5 or x = √5