Роздiл 2. Вирази i тотожностi » 257

Обчисліть 1) 15^7/(9^3 • 5^8 ) = (3^7 • 5^7)/(3^6 • 5^8 ) = (3^6 • 5^7• 3)/(3^6 • 5^7• 5) = 3/5; 2) 42^6/(28^5 • 9^3 ) = 〖(3 • 2 • 7)〗^6/(〖(2 • 2 • 7)〗^5 • 3^6 ) = (3^6 • 2^6• 7^6)/(3^6 • 2^10 • 7^5 ) = (3^6 • 2^6• 7^5 • 7)/(3^6 • 2^(6 )• 7^5 • 2^4 ) = 7/16; 3) (10^4 • 18^5)/(36^4 • 5^3 ) = (〖(2 • 5)〗^4 • 〖(2 • 9)〗^5)/(〖(2 • 2 • 9)〗^4 • 5^3 ) = (2^4 • 5^4• 2^5 • 9^5)/(2^4 • 2^4 • 9^4 • 5^3 ) = (2^9 • 5^4 • 9^5)/(2^8 • 9^4 • 5^3 ) = (2^8 • 5^3 • 9^4 • 2 • 5 • 9)/(2^8 • 9^4 • 5^3 ) = 90; 4) (21^4 • 40^3)/(140^3 • 15^4 ) = (〖(3 • 7)〗^4 • 〖(20 • 2)〗^3)/(〖(20 • 7)〗^3 • 〖(3 • 5)〗^4 ) = (3^4 • 7^4• 20^3 • 2^3)/(20^3 • 7^3 • 3^4 • 5^4 ) = (7^4 • 2^3)/( 7^3 • 5^4 ) = (7^3 • 2^3 • 7)/( 7^3 • 5^4 ) = (2^3 • 7)/( 5^4 ) = 56/625.