1. Simple, x-1> 0，2-x & lt； 0 and so on, as long as there is an inequality symbol.

2.( 1) is not negative, so it is positive and zero. a≥0

(2)c & gt； A and c>b

(3)x+ 17 & lt； 5x

1.( 1)3x+8 & gt； 5x

(2)x^2≥0

(3) y represents the area of ocean, x represents the area of land, y >；; x

(4) Let the teacher's age be Y and your age be X, y & gt2x.

(5) Let football quality be A and basketball quality be B, then A >；; b

2. 1+3, 1+5, 1+7,3+5

3. Practical background, examples of daily life

For example, the mass of 1 hot water kettle and 1 cup is less than or equal to 5 kg.

2 wooden chairs plus 1kg is greater than or equal to 3kg.