7,5 * 2 целых 31/40: 16,65+0,25

1) 7,5*2³¹/₄₀=75/10*111/40=75*40/(111*10)=3000/1110=300/111.2)  300/111:16,65=300/111:1665/100=300*100/(111*1665)=30000/184815=6000/36963=2000/123213) 2000/12321+0,25=2000/12321+1/4=(2000*4+1*12321)/(12321*4)=20321/49284.