Answer:
a = ±10/9
Step-by-step explanation:

Answer:
x = 8
Step-by-step explanation:
you have similar triangles here
so 2 is to 4 as 4 is to x
2/4 = 4/x
x = 8
Answer: On the 29th day
Step-by-step explanation:
According to this problem, no lilypad dies and the lilypads always reproduce, so we can apply the following reasoning.
On the first day there is only 1 lilypad in the pond. On the second day, the lilypad from the first reproduces, so there are 2 lilypads. On day 3, the 2 lilypads from the second day reproduce, so there are 2×2=4 lilypads. Similarly, on day 4 there are 8 lilypads. Following this pattern, on day 30 there are 2×N lilypads, where N is the number of lilypads on day 29.
The pond is full on the 30th day, when there are 2×N lilypads, so it is half-full when it has N lilypads, that is, on the 29th day. Actually, there are
lilypads on the 30th, and
lilypads on the 29th. This can be deduced multiplying succesively by 2.
Walking 10 blocks consumes 75 calories so... You add another 75 wich is calories and then divide 75/2. 75+75+37.5=187.5 calories!