What is 5x + 3y = 12 written in slope intercept form

The jewelry store is having a sale. necklaces that were regularly priced at $23.50 are on sale for $18.80. what is the percentage of decrease in the price of necklaces?

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).

Me! i really need to get this right before 9. prove the divisibility of 7^6+7^5-7^4 by 11. use factoring so you get a number times 11. just tell me the number. i need this done asap