Question

Solve : x^4 - 13x² +42 = 0​

Answer 1

Answer:

let x^2 be y

y^2-13y+42=0

y^2-7y-6y+42=0

y (y-7)-6 (y-7)=0

(y-7)(y-6)=0

y=7;6

x^2=7;x^2=6

x=root 7;x=root 6

Answer 2

Answer:

x=root7 x=root6

Step-by-step explanation: