Вправи: 20.14

20.14 Спростіть вираз:

1) 4а^–8b⁷ • 5а¹⁰b^–3 = 20а²b⁴;

2) 10m^–6n⁴ • 0,4m⁶n^–9 = 4m⁰n^–5 = 4n^–5;

3) 13x^–4y⁶ • (–9x⁵y^–3) = –3xy³;

4) (–27b^–6m^–4) • (–116b^–4m^–2) = 13b^–10m^–6.