Вычислите используя законы умножения а) (47•1/26)•13/27-(20•1/26)•13/27 = б) (2/3•4/5)•(3/4•5/6)•(6/7•8/9)•(7/8•9/10) = за ранее ! ^_^

а) (47•1/26)•13/27-(20•1/26)•13/27 =27/54=1/2=0,5
б) (2/3•4/5)•(3/4•5/6)•(6/7•8/9)•(7/8•9/10) =1/5=0,2

(47•1/26)•13/27-(20•1/26)•13/27 = (1/26*13/27) * (47-20)= 1/54*27=1/2
1/26*13/27= 1/54

(2/3•4/5)•(3/4•5/6)•(6/7•8/9)•(7/8•9/10) = (2/3*3/4)*(4/5*5/6)*(6/7*7/8)*(8/9*9/10)=
= 1/2*2/3*3/4*4/5= (2/3*3/4)*(1/2*4/5)= 1/2*2/5=1/5