because in the first equation it is saying that 4x+5 is also equal to the second equation, -1/3x-8. then you would do -1/3x-8=4x+5, then(letters to the left) -4x on bothe sides,which then you get -13/3x-8=5, then +8 on both side, then you get -13/3x=13, last you divied by -13/3 and youj get x=-3
