Вправи 301 - 400 » 359 (9-11)

9) 64–4 • 412 • 16–2 • x = 4–12 • 165; (43)–4 • 412 • (42)–2 • x = 4–12 • (42)5; 4–12 • 412 • 4–4 • x = 4–12 • 410; 4–4 • x = 4–2; x = 4–2 : 4–4; x = 42. 10) x = (27^(-5)•9^3 )/81^(-2) = (〖(3〗^3 )^(-5)• 〖(3〗^2 )^3)/(〖(3〗^4 )^(-2) ) = (3^(-15)•3^6 )/3^(-12) = 3^(-9)/3^(-12) = 33; 11) (0,25x)10 = (11/3)–10; (1/4x)10 = (4/3)–10; (1/4x)10 = (3/4)10; 1/4x = 3/4; x = 3/4 : 1/4; x = 3.