1) (x+2.3)*0.2=0.7 3) 4.2x+8.4=14.7
0.2x+0.46=0.7 4.2x=14.7-8.4
0.2x=0.7-0.46 4.2x=6.3
0.2x=0.24 x=6.3:4.2
x=0.24:0.2 x=1.5
x=1.2
2) (2.8-x):03x=5 4) 0.39:x-0.1=0.16
2.8-x=5*0.3x 0.39:x=0.16+0.1
2.8-x=1.5x 0.39:x=0.26
2.8=1.5x+x 0.39=0.26*x
2.8=2.5x 0.26x=0.39
x=2.8:2.5 x=0.39:0.26
x=1.12 x=1.5
43/9= 4 7/9 ; 121/12= 10 1/12; 60/5=11 5/5
23,12-1,9=21,22; 3,7+0,42=4,12
0,18×0,7=0,126; 1,68÷0,6=2,7