Answers:
Row 0: 1
Row 1: 1 1
Row 2: 1 2 1
Row 3: 1 3 3 1
Row 4: 1 4 6 4 1
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Explanation:
This is known as Pascal's Triangle. Each value, other than the '1's, is found by adding the values directly above it. For instance, the '4' is the result of 1+3, and the 6 is a result of 3+3, and so on.
You can use the nCr combination formula to find the same values.
Alternatively you can expand out binomials of the form (x+y)^n, for integer values of n, and you'll find the coefficients of the terms match perfectly with Pascal's Triangle.
The graph of the function f(x)=(x+2)(x+6) is shown
The statement the function is negative for all real values of x where x <-2
Answer:
Riley divided the number of petunia seeds by the number of begonia seeds, getting
. What you actually need to do to calculate the probability of selecting a petunia seed is divide the number of petunia seeds by the <em>total</em> number of seeds. 5 petunia seeds and 15 begonia seeds makes 20 total seeds, so you divide 5 petunia seeds by 20 total seeds to get
.
First part of the race
speed1, s1 = 8.75 km/h
distance1 = 5 km - x
time 1 = 0.65 h - t
Second part of the race
speed2, s2 = 6 km/h
distance2 = x
time2 = t
s2 = x/t = 6 ⇒ t = x / 6
s1 = [5 - x] / [0.65 - t] = 8.75
5 - x = 8.75 [0.65 - t]
5 -x = 8.75(0.65) - 8.75t
5 - x = 5.6875 - 8.75 (x/6)
5 - x = 5.6875 - 1.4583x
1.4583 x - x = 5.6875 - 5
0.4583 x = 0.6875
x = 0.6875 / 0.4583 = 1.5