Answer:
отлично вы молодец болшая у вас всё правилно
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
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If the bathtubs in your "draining race" start with the same level, the one with the steepest slope (-0.5 cm/s) will win.
Think about it this way, what is 5x3??? 15 right. Ok then what is 5x30???? 150. So the store should sell each soccer ball for $5 each:)
M(x, y) = ((x1 + x2)/2, (y1 + y2)/2) = ((-2 + 4)/2, (5 - 9)/2) = (2/2, -4/2) = (1, -2)