(1)
:4=x:3.5 4 5
4x=
×3.54 5
4x÷4=2.8÷4
x=0.7;
(2)0.2:
=16 9
:x1 20
0.2x=
×16 9
1 20
0.2x÷0.2=
÷0.24 45
x=
;4 9
(3)
:x=0.9:4.23 2
0.9x=
×4.23 2
0.9x÷0.9=6.3÷0.9
x=7;
(4)x:
=6 25
:1.81 9
1.8x=
×6 25
1 9
1.8x÷1.8=
÷1.82 75
x=
2 135