1) (1,1х²-6y)² -(1.1x² -6y)(1.1x²+6y)=(1,1х²-6y)(1,1х²-6y-1,1х²-6y)=
=-12у*(1,1х²-6y)
2) (2,3а -7b³ )(2.3a +7b³) -(2.3a +7b³)²= (2.3a +7b³) (2.3a -7b³-2.3a -7b³) =
=-14b³*(2.3a +7b³)
3) (3.1n³-5m )² +(5m-3.1n³)(5m-3.1n³)=(3.1n³-5m)² -(-5m+3.1n³)(5m-3.1n³)=
=(3.1n³-5m)(3.1n³-5m-5m+3.1n³)=(3.1n³-5m)(6.2n³-10m)