Answer:
in this form, the "-r" would cause the result to decrease
I assume that the answer is "r"
if r = .1 (10 %) then 1-.1 = .9
if you have 100 items then y = 100(.9)^1 = 90
the total decreased by 10% ... y = 100(.9)^2 after 2 time periods
Step-by-step explanation:
Hi there!

We know that the equation for the volume of a pyramid is:
V = 1/3(bh)
We know that:
V = 200 km³
b = 12 × 5 = 60 km²
We can plug these into the equation:
200 = 1/3(60)(h)
Simplify:
200 = 20h
Divide both sides by 20:
200/20 = 20h/20
h = 10 km
The second equation is correct. Nina initally had 17 marbles in her bag. Her mother placed m marbles into her bag. After counting, she now has 34 marbles. Part of this 34 marbles is already her initial 17 marbles. Therefore, 17 marbles initially + m unknown marbles = 34 marbles. The equation <span>17 + m = 34 is the answer.</span>