81-mˇ4=3ˇ4-mˇ4=(3ˇ2+mˇ2)(3ˇ2-mˇ2)=(9+mˇ2)(3+m)(3-m)
3xˇ5-3x=3x(xˇ4-1)=3x(xˇ2+1)(xˇ2-1)=3x(xˇ2+1)(x+1)(x-1)
2aˇ4b-2bˇ5=2b(aˇ4-bˇ4=2b(aˇ2+bˇ2)(a+b)(a-b)
3aˇ5b-3abˇ5=3ab(aˇ4-bˇ4)=3ab(aˇ2+bˇ2)(a+b)(a-b)
xˇ4-xˇ2=0, xˇ2(xˇ2-1)=0,xˇ2(x+1)(x-1)=0
x1=0,x2=-1,x3=1
9yˇ2-4yˇ4=0,yˇ2(9-4yˇ2)=0,yˇ2(3+2y)(3-2y)=0
y1=0,y2=-3/2=-1,5, y3=3/2=1,5