Solve groups of inequalities and represent their solution sets on the number line.

Solution: <>

Solve inequality , x 1, solve inequality , x 3, on the number line as follows:

So, the solution set of the inequality group is 1 x 3.

Concept: Inequality.

Equations that are connected with "greater than", "less than", "unequal", "greater than or equal to", or "less than or equal to" and have a magnitude relationship are called inequalities.

Inequality groups. Several inequalities are linked together and are called inequality groups. (Note: When there is a method.)

To solve the inequality group, you can first calculate the inequality in it one by one to calculate the respective solution set, and then represent it on the number line.

Take, for example, a group of inequalities consisting of two inequalities:

If the solution set of two unknowns is represented in the same left direction on the number line, then the solution set of the unknown on the left is the solution set of the inequality group, which is "the same small takes the smaller".

If the solution set of two unknowns is represented in the same direction to the right on the number line, then the solution set of the unknown on the right is taken as the solution set of the inequality group, which is "the same big takes the big".

If the solution set of two unknowns intersects on the number line, the value between them is taken as the solution set of the inequality group. If x represents the solution set of the inequality, which is generally expressed as a If the solution set of two unknowns is facing back on the number line, then the solution set of the inequality group is an empty set, and the inequality group has no solution. This is "taking emptiness from the back".

Solution inequality group: <>

And the set of its repentance is represented on the number axis of the front rock. To solve the inequality, to <> to solve the inequality, to get the <>

The solution set of the inequality group <>

The set of solutions for this group of equations is represented on the number line as follows:

1≤x＜2．

Equations that are connected with "greater than", "less than", "unequal", "greater than or equal to", or "less than or equal to" and have a magnitude relationship are called inequalities.

Several inequalities are joined together and are called inequality groups (note: when there is an a-number axis is a specific geometric figure; The three elements of the number axis, such as the origin, the positive direction, and the unit length, are indispensable.

1) From the origin, the point on the ray in the positive direction (positive semi-axis) corresponds to a positive number, and the point on the ray in the opposite direction (negative semi-axis) corresponds to a negative number, and the origin corresponds to zero.

2) For two numbers represented on the number line, the number in the positive direction is always greater than the number on the other side.

3) Positive numbers are greater than 0, negative numbers are less than 0, and positive numbers are greater than all negative numbers.

Note: The unit length refers to taking the appropriate length as the unit length, for example, you can take 2m as the unit length "1", then 4m means 2 unit lengths. The unit of length refers to the unit of length such as meters, centimeters, millimeters, etc.

The two should not be confused.

Points and numbers on the number line correspond one-to-one. (Any number, including imaginary numbers, can be represented by a point on the number line.) ）

The positive direction of the number axis is generally to the right, but the possibility of going to the left is not excluded, and the number closer to the positive direction is the larger, and the farther away from the positive direction is the smaller the number.

When drawing the number axis, it is generally necessary to draw the horizontal line and the positive direction first, then draw the zero, and then draw the unit length according to the inscription.

Solution: Solve the inequality get: <>

Solve the inequality to get: <>

So the set of solutions for this group of inequalities is <>

The set of solutions for this group of inequalities is expressed on the number line as.

Solution: Cause: <>

<> Reason: <>

<> the solution of the original inequality group is burned into: leather bucket <>

Solution: Rolled by the leather bucket: <>

That is<> justification: <>

That is<> the solution of the original inequality burns this mill as a <>

It is expressed on the number line as: