Question

X^4-45x^2+324

Answer 1

what is your question?

Answer 2

we have to solve for f(x)=0,draw graph or what ?

Answer 3

324 = 2*2*9*9

- this will help you factorise your expression
you need -45 as the sum of 2 numbers whose product is 324

Answer 4

inspection shows it to be -2*2*9 and - 9

that is -36 and -9
so
X^4-45x^2+324 = x^4 - 36x^2 - 9x^2 + 324

= (x^2 -36)(x^2 - 9 )

Answer 5

Another way is to set x^2 = z and you have a quadratic to solve..