17:(3\5+1\4)+(7\8-1\4)*(4\5)

17:(3\5+1\4)+(7\8-1\4)*(4\5)==17:( (12+5)/20)+( (14-4)/16)(4/5)==17:(17/20)+( (10*4)/(16*5)==(17*20)/17+2/4==20+0,5==20,5вроде бы так :)

17:(3/5 + 1/4) + (7/8 - 1/4)*(4/5)= 20 1/217: (12/20+5/20)=17: 17/20=340/17=207/8-2/8=5/85/8*4/5=20/40=1/220+1/2=20 1/2