If you can, you can try visiting your local public library and print whatever it is you need (though you might need to pay) or simply go to your school's library and print there if it's allowed.
I hope this helps :-)
A is the mid point ==> AL = AB = 2AB
6x-17=2(2x+3) => 6x -17 = 4x +6 => 2x = 23 =>x=23/2
then just plug x into LB and AB