4x:0.4=0.5:3/5 4x*3/5 =0.5*0.412/5*x=0.2x=1/5*5/12x=1/121/2:1/3=1/4:x 1/2*x=1/3*1/4:1/2*x=1/12x=1/12*2x=1/640%:x=(1+1/7):5/6 8/7*x=40%*5/6 8/7*x=2/5*5/6 8/7*x=1/3x=1/3*7/8x=7/2475%:(x+1)=1/4x+1=75%*4x...