①x:1.25= 0.4:
②75%x+3.6=5.1
x+50%x=7.5
①3x-3.7=21.2 %x+40×0.12=6
x÷4=÷30% 3x-0.75=6.75
5x-20%x=19.2
8x-19=53 0.25∶x=1.6∶2.4 x-20%x=0.6