②x: =4: .
0.8x+0.7=7.9 :x=0.6:
3.5x+0.8=2.2
7x+3×16=69 8:x=4:0.8
x+50%x=120÷2
x=( )
x÷25%-30=50
x=
①1.5x-2.8=4.7
②
③12: =
x÷(1﹣ ﹣25%)=2 .
1 :4=x:2.5; 4.9+50%x=6.3; 6.9﹣ x= .