Вправи 201 - 342 » 268

268. Знайдіть значення виразу: 1) 6–9 • 66 = 6–9+6 = 6–3 = 1/6^3 = 1/216; 2) 7–16 : 7–18 = a–16–(–18) = 72 = 49; 3) 5–7 : 5–6 • 52 = 5–7–(–6)+3 = 52 = 25; 4) (4^(-7)•(4^(-5) )^3)/((4^(-3) )^7 ) = (4^(-7)• 4^(-15))/4^(-21) = 4–7+(–15)–(21) = 4–1 = 1/4; 5) 0,8–4 • (11/4)–4 = (4/5)–4 • (5/4)–4 = (4/5 • 5/4)–4 = 1–4 = 1; 6) 11^(-2)/22^(-2) = 11^(-2)/(2^(-2) • 11^(-2) ) = 1/2^(-2) = 1 : 1/4 = 4.