In the controlled experiment, a scientist is studying how long it takes parachutes of different sizes to fall to the ground. what are the manipulated/experimental variables?

The size of the parachutes.

Explanation: In this experiment we have two variables: The size of the parachute and the time that the parachute needs to cover a given distance (from a plane to the ground, for example)

The only thing that the scientist can modify, the independent variable, is the size of the parachute, and this will impact in the dependent variable, the time it needs to fall to the ground.

answer: a) y=-8x+5

a) m= -8

b) m= -2

c) m= 7

d) m= 6

the total distance that martina travels that day is

(distance from home to mom's office) plus (distance from mom's office to school)

plus (distance from school to library) plus (distance from library to friend's house)

plus (distance from friend's house to martina's house).

(we don't know what any of these distance actually is.)