Which situation involves a change modeled by a positive number but an end result modeled by a negative number? Leo enters an elevator on the second floor and goes down four floors.
A plane, flying at an altitude of 300 feet, descends 50 feet.
Irene is scuba diving at –30 feet. She swims 10 feet toward the surface to watch a school of fish.
April owes her brother $5. On Friday, she gets $10 for her allowance.

Consider the system: y = 3x + 5 y = ax + b what values for a and b make the system inconsistent? what values for a and b make the system consistent and dependent? explain

You drop a rubber ball off the roof of a 50 meter high building onto a paved parking lot. it bounces back up with every bounce, but not quite all the way back up to you. after the first bounce it bounces back only 80 percent of the distance it was dropped from. the pattern continues, meaning after every bounce it comes up to just 80 percent of the previous maximum height. so if before the first bounce the height is 50 meters, what height does the ball reach after the fifth bounce? round your answer to one decimal place and chose the correct response from the choices below:

Masons cell phone company charges $0.12 for every text message he sends plus $2.50 per month if mason sent 25 messages this month how much money does he owe the one with the correct answer and explanation gets 10 points and is marked as the brainliest answer