1) Simplify:
a) (y- 5) (y+5) (y2 + 25)
b) ( m^2 – n^2 m)^2 + 2m^2 n^2
c) 2y (3y – 5) (2y +1)
d) ( 7m – 8n)^2 + (7m + 8n)^2