Which matrix will always give a determinant of 0? a matrix having all nonzero numbers
a matrix not being the identity matrix
a matrix not having equal rows
a matrix having two equal rows

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).