Вправи: 1264

1264. Спростіть вираз:

1) 4a³ab – 6a²b³b³ – 5ab ∙ 3a + 7a³b ∙ 0,2b⁴ = 4a⁴b – 6a²b⁶ – 15a²b + 1,4a³b⁵;

2) 11m² ∙ 2mn – 9mn ∙ 6mn³ + 10mnm = 22m³n – 54m²n⁴ + 10m²n;

3) 8xx⁴x ∙ (–14xy) + 18xy ∙ 79yx5 = –2x⁷y + 14x⁶y²;

4) 9x³xy² – 8xy²y⁸ + 12x²y ∙ 4y – 0,4xy³ ∙ 6x³y² = 9x⁴y² – 8xy¹⁰ + 48x²y² – 2,4x⁴y⁵.