Problem : 
Factor 2x4 -2y4.
2(x2 + y2)(x + y)(x - y)
 
Problem : 
Factor 4x4 -9y4.
(2x2 +3y2)(2x2 -3y2)
 
Problem : 
Factor 9x6 -16y6.
(3x3 +4y3)(3x3 -4y3)
 
Problem : 
Factor x6 - y6.
(x + y)(x - y)(x2 - xy + y2)(x2 + xy + y2)
 
Problem : 
Factor x4 +2x2 - 24.
(x + 2)(x - 2)(x2 + 6)
 
Problem : 
Factor 28x4 -18x2 + 2.
2(7x2 -1)(2x2 - 1)
 
Problem : 
Factor 4x5 +16x3 + 15x.
x(2x2 +5)(2x2 + 3)