Please explain the steps to solve I need help actually learning it

Answer:
Hello!!! Princess Sakura here ^^
Step-by-step explanation:
If you take a look you can see that the whole line is 17..um....units. The 2x-4 and the 2x-7 are together on the line is if you add them together you should end up with 17 units.
[tex]2x-4+2x-7=17\\4x-11=17\\4x=28\\x=7[/tex]
So the value of x is 7, but if you wanted to know what each line measures you'll have to plug it in. For example line AB will measure 10 units.
[tex]2x-4\\2(7)-4\\14-4\\10[/tex]