§ 12: 12.11

12.11 Скоротіть дріб:

1) a12 - 2b12a12 + 2b12 a12 + 2b12 = a12- 2b12;

2) a12 - b12a12 + 2b12 a12b12a12 + b12 = a12 - b12a12b12;

3) (2c13 - 3d13)2(2c13 - 3d13) = 2c13- 3d13;

4) m12 - n12(m12)3- (n12)3 = (m12 - n12)m12 - n12(m + m12n12 + n) = 1m + m12n12 + n;

5) a12(a14+ 7)a12(a12- 49) = (a14+ 7)(a14- 7)(a14+ 7) = 1a14- 7;

6) 615 • 515- 615215 • 515- 215 = 615( 515- 1) 215( 515- 1) = 315 • 215215 = 315.