Solve x4 - 11x2 + 18 = 0.

x=√2, x=-√2, x= 3 and x=-3

Step-by-step explanation:

We need to solve the equation x^4 - 11x^2+18=0  

We can replace x^4 = u^2 and x^2 = u

So, the equation will become

u^2 -11u+18 = 0

Factorizing the above equation:

u^2 -9u-2u+18 =0

u(u-9)-2(u-9)=0

(u-2)(u-9)=0

u=2, u=9

As, u = x^2, Putting back the value:

x^2 =2 , x^2 =9  

taking square roots:

√x^2 =√2 ,√x^2=√9  

x=±√2 , x = ±3

so, x=√2, x=-√2, x= 3 and x=-3

The second answer is correct.

Step-by-step explanation:

Mark brainliest if correct please

answer: all of the odd numbers were opened

the first person was the one that was opening all of the lockers. since one is odd, this causes all of the odd number lockers to be opened in the end.