Вправи 301 - 400 » 391

391. Спростіть вираз: 1) (a + b)–5 • (a – b)–5 = ((a + b)(a – b))–5 = (a2 – b2)–5; 2) (2/z)–2 • (z/3)–2 = (2/z • z/3)–2 = (2/3)–2 = (3/2)2 = 1,52 = 2,25; 3) (n/(n+1))–5 • ((n+1)/n)–5 = (n/(n+1) • (n+1)/n)–5 = 1–5 = 1; 4) (b/(c+ a))–3 • ((2a+2c)/b)–3 = ((b•(2a+2c))/((c+ a) • b))–3 = ((2(a+ c))/(a+ c))–3 = 2–3 = 1/8; 5) p–4 • ((p+2)/p)–4 • (1/(p+2))–4 = p–4 • ((p+2)/p • 1/(p+2))–4 = p–4 • p4 = p0 = 1; 6) (x/(x+1))–1 : (x^2/(x+1))–1 = (x+1)/x : (x+1)/x^2 = (x+1)/x • x^2/(x+1) = x.