Is there a minimum value for junior high school mathematics

Solution: If x= 1,

Then | x- 1 |+| x-3 |

=| 1- 1|+| 1-3|

= 0+2

= 2

If x=3,

Then | x- 1 |+| x-3 |

=|3- 1|+|3-3|

= 2+0

= 2

If x=2

Then | x- 1 |+| x-3 |

=|2- 1|+|2-3|

= 1+ 1

But if x < 1 or x > 3

If x=0,

Then | x- 1 |+| x-3 |

=|0- 1|+|0-3|

= 1+3

= 4

Such as x=- 1,

Then | x- 1 |+| x-3 |

=|- 1- 1|+|- 1-3|

= 2+4

If x=4,

Then | x- 1 |+| x-3 |

=|4- 1|+|4-3|

=3+ 1

∴x can only be a rational number not less than 1 and not more than 3.

The minimum value of x- 1 |+x-3 | is 2.