1. 9b(b -1) -(3b+2)² =9b² -9b -(9b² +12b +4) =9b² -9b -9b² -12b -4 = -21b -42. a) 121 -m² =(11 -m)(11+m)b) 16x² -8x +1 =(4x -1)² =(4x -1)(4x -1)3. y(y -1) -(y -5)² =2y² -y -(y² -10y +25) =2y² -y -y² +10y -25 =29y -25 =29y =2 +259y =27y =27/9y =34. a) (0.2x +10y)(10y -0.2x) = -0.04x² +100y²b) (-0.8 -0.5)² =(-1.3)² =1.695. a) (2x -3)² -(7 -2x)² =2(2x-3 -(7-2x))(2x-3 +(7-2x)) =2(2x-3-7+2x)(2x-3+7-2x) =2(4x -10)*4 =24x -10 =2/44x -10 =0.54x =0.5+104x =10.5x =2.625или4x² -12x+9 -(49 -28x+4x²) =24x² -12x+9 -49+28x -4x² =216x -40 =216x =42x =2.625ответ: x =2.625b) 16x² -49 =0(4x -7)(4x +7) =04x -7 =0, 4x =7, x =7/4 =1.754x+7 =0, 4x= -7, x = -1.75ответ: x= -1.75, x =1.756. a) 36a² -144p^10n^6 =36(a² -4p^10n^6) =(a -2p^5n^3)(a+2p^5n^3) b) 49x² -(y+8x)² =(7x -(y+8x))(7x +(y+8x)) =(7x -y-8x)(7x+y+8x) =(-x -y)(15x+y)