If y = 5 when x = -3, find x when y = -12 I've spent the past few minutes figuring it out, but I can't figure out what to do because 5 doesn't go into 3.

Aquantity with an initial value of 3900 decays exponentially at a rate of 35% every hour. what is the value of the quantity after 0.5 days, to the nearest hundredth?

Atruck can be rented from company a $50 a day plus $0.60 per mile. company b charges $20 a day plus $0.80 per mile to rent the same truck. find the number of miles in a day at which the rental costs for company a and company b are the same

(25 ! ) what does it mean for an equation to have no solution or infinitely many solutions?