1﹣20%x=1.6; 4:x=2:1.2; 5x﹣ x= .
①6x-18=36
②x- x=2
③ =
①1.5x-2.8=4.7
②
③12: =
①7∶5和8∶6
②10∶9和0.2∶0.18
x=