Вправи: 20.15

20.15 Спростіть вираз:

1) 10m³n^–2 • 2m^–5n⁴ = 20m^–2n²;

2) 0,02а^–8b³ • 100a⁸b^–7 = 2a⁰b^–4 = 2b^–4;

3) –18x^–3y⁷ • 16x⁴y^–10 = –2xy^–3;

4) (–114p^–3c^–5) •(–25p^–2c^–3) = 12p^–5c^–8.