Which property does each equation demonstrate? x2 + 2x = 2x + x2 (3z4 + 2z3) – (2z4 + z3) = z4 + z3 (2x2 + 7x) + (2y2 + 6y) = (2y2 + 6y) + (2x2 + 7x)

Darcy deposited $390 into a savings account. as long as the account balance remains at or above $150, she does not have to pay a service fee for the account. for how many months can she withdraw $40 a month without having to pay service fees? a) 3 b) 5 c) 6 d) 9