HEP PLEASE !! DUE IN A MINUTE

Consider the proof. given: segment ab is parallel to line de. prove: what is the missing statement in step 5?

Each month, a shopkeeper spends 5x + 14 dollars on rent and electricity. if he spends 3x−5 dollars on rent, how much does he spend on electricity? for which value(s) of x is the amount the shopkeeper spends on electricity less than $100? explain how you found the value(s).

Solve x+3y=6 and 4x-6y=6 by elimination . show work !