1.(3x-5)²-(3x-1²)² 2.(5+x) (5-x)

1.(3x-5)²-(3x-1²)² 2.(5+x) (5-x)

원형=(3x-5+3x-1)(3x-5-3x+1)
=(6x-6)*(-6)
=-36x+36
오리지널=5&\#178;-x²
=25-x²