1, the original formulas =3 and 9 4-2 and 17, 1 1+2 and 5-9.

=(3 and 4+2 and 5/9)-2 and 65438+ 1 1.

=6-2 and 17 parts 1 1

=3 65438+6/07

2. The original formula = (2/3+9× 9/28 )×165438+12/0.

= (2/3+ 1) × 165438+ 12/0.

= 12 point11×11point 12 point

= 1

3. The original formulas = 1 and 2/3× [7 and 5/6+ 14 and 5-3 and 1-4 and 1].

= 1 and 2/3× [7 and 5/6+ 1 and 2/6 1-4 and 1]

= 1 2/3 × [7 5/6 7 1]

= 1 and 2/3× 15

=25

4.0.4x= 1 plus 7 1×3 plus 2 1

0.4x=4

x= 10