Question

两道一元二次方程

1) -x^2+26x-120=0 2) 9x^4-35x^2-4=0

Answer 1

-x^2+26x-120=0
x^2-26+120=0
(x-20)(x-6)=0
x1=20
x2=6

9x^4-35x^2-4=0
(9x^2+1)(x^2-4)=0
(9x^2+1)9x+2)(x-2)=0
x1=-2
x2=2

Answer 2

1
-x²+26x-120=0
x²-26x+120=0
(x-20)(x-6)=0
x1=6,x2=20

2\
9x^4-35x²-4=0
(9x²+1)(x²-4)=0
(9x²+1)(x+2)(X-2)=0
9x²+1>0
所以
x1=-2,x2=2