Вправи: 391

391. Спростіть вираз:

1) (a + b)^–5 • (a – b)^–5 = ((a + b)(a – b))^–5 = (a² – b²)^–5;

2) (2z)^–2 • (z3)^–2 = (2z • z3)^–2 = (23)^–2 = (32)² = 1,5² = 2,25;

3) (nn+1)^–5 • (n+1n)^–5 = (nn+1 • n+1n)^–5 = 1^–5 = 1;

4) (bc+ a)^–3 • (2a+2cb)^–3 = (b•(2a+2c)(c+ a) • b)^–3 = (2(a+ c)a+ c)^–3 = 2^–3 = 18;

5) p^–4 • (p+2p)^–4 • (1p+2)^–4 = p^–4 • (p+2p • 1p+2)^–4 = p^–4 • p⁴ = p⁰ = 1;

6) (xx+1)^–1 : (x2x+1)^–1 = x+1x : x+1x2 = x+1x • x2x+1 = x.