1)7:8=х:98; 2)у:1.5/31=7.3/4:1/3; 3)а/0,6=25/3; 4)2+t/5=4/9;

1) 7:8=х:987*98=8хх=98*7/8х=85,753) а/0,6=25/33*а=0,6*253а=15,6а=15,6/3а=5,24) 2+т/5=4/9т/5=4/9-2т/5=4/9-18/9т/5=-14/9т=-14*5/9т=-70/9т=-7 7/9