Вправа 454 алгебра Бевз гдз 7 клас

№ 454

а) 9c³x² + 2c³x – c³ + 9x² + 2x – 1 = (9c³x² + 2c³x – c³) + (9x² +
+ 2x – 1) = c³(9x² + 2x – 1) + (9x² + 2x – 1) = (9x² + 2x – 1)(c³ + 1);
б) 4abc² – 4ac + 4b + abc²x – acx + bx = (4abc² – 4ac + 4b) +
+ (abc²x – acx + bx) = 4(abc² – ac + b) + x(abc² – ac + b) =
= (abc² – ac + b))(4 + x);
в) x³ + x²y + x³y – xy³ – xy² – y³ = (x³ + x²y + x³y) – (xy³ + xy² +
+ y³) = x²(x + y + xy) – y²(xy + x + y) = (x + y + xy)(x² – y²) =
= (xy + x + y)(x – y)(x + y);
г) x² – x³ + y – y² – xy + xy² = x² – x³ + y – xy – y² + xy² =
= x²(1 – x) + y(1 – x) – y²(1 – x) = (1 – x)(x² + y – y²).