18. Примените распределительный закон и сократите дробь: а) (5*16 - 5*7)/15; б) (4*15 - 4*7)/12; в) (9*13 + 9*4)/15*17; г) (12*13)/(8*11 + 8*2); д) (14*7-5*14)/(21*8+21*4); е) (24*2+4*24)/(36*9-7*36)

а) (5*16 - 5*7)/15 = 5*(16-7)/15 = 5*9/15 = 45/15 = 3 б) (4*15 - 4*7)/12 = 4*(15-7)/12 = 4*8/12 = 32/12 = 8/3 в) (9*13 + 9*4)/(15*17) = 9*(13+4)/(15*17) = 9*17/(15*17)= 9/15= 3/5 г) (12*13)/(8*11 + 8*2) = (12*13)/8*(11+2)=12*13/8*13 = 12/8 = 3/2 д) (14*7-5*14)/(21*8+21*4) = 14*(7-5)/(21*(8+4)) = 14*2/(21*12) = 28/252= 1/9 е) (24*2+4*24)/(36*9-7*36) = 24*(2+4)/(36*(9-7)) = 24*6/(36*2) = 144/72 = 2