If x2-3x+2 be factor of x4-px2+q, then (p,q)=
[3, 4]
[4, 5]
[4, 3]
[5, 4]
x2-3x+2 be factor of x4-px2+q=0
Hence (x2-3x+2)=0⇒(x-2)(x-1)=0
⇒x=2, 1, putting these values in given equation
so 4p-q-16=0 ....(i)
and p-q-1=0 ..(ii)
Solving (i) and (ii), we get [p,q]=[5,4]