4/45:(12/25-4/15)+15/16*4/15 = 4/45:[(12*3-4*5)/75]+(15*4)/(16*15)== 4/45 : [(36-20)/75]+4/16=4/45 : 16/75 + 1/4 = (4*75) / (45*16) + 1/4 =
= (1*5)/(3*4) + 1/4 = 5/12 + 1/4 = (5+3)/12 = 8/12 = 2/3
4/45:(12/25-4/15)+15/16*4/15 = 4/45:[(12*3-4*5)/75]+(15*4)/(16*15)=
= 4/45 : [(36-20)/75]+4/16=4/45 : 16/75 + 1/4 = (4*75) / (45*16) + 1/4 =
= (1*5)/(3*4) + 1/4 = 5/12 + 1/4 = (5+3)/12 = 8/12 = 2/3