Answer:
Step-by-step explanation:

Plot the points(0 ,-4) , (5 , -5) and (-5 , -3 ) in the graph and join the points.
Step 1: Read and understand the problem statement.
You are given (time, depth) pairs of (20 s, 8 cm) and (40 s, 0 cm) and asked to write an equation that describes the relationship of depth (y) to time (x).
The rate of change is (0 cm -8 cm)/(40 s -20 s) = -8 cm/(20 s) = -2/5 cm/s. Then in point-slope form using the second point, the linear function rule is
y = (-2/5)(x -40) +0
You can expand this to
y = (-2/5)x +16
y = -0.4x +16 . . . . . . using a decimal number for the slope
_____
If the bathtubs in your "draining race" start with the same level, the one with the steepest slope (-0.5 cm/s) will win.
50 divided by 40 equals 1.25! So the car is going 1.25 mph
2x2+2x-1=
4+2(-3)-1=
4+(-6)-1=
4+(-7)=
-3
Answer:

where x = number of adults
y = number of children
and the extra weights of 4kg of each person.