Please do this math for me or else i will steal your cookies

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).

Adam used 1072.4 gallons of water over the course of 7 days. how much water did adam use, on average, each day?

Find the missing dimension! need asap! tiny square is a =3025 in ²