Explanation:
a)
b) First, we have that
On the other hand,
Therefore, both expressions are equal. This makes sense, because selecting k elements from a group of n is the same than specify which elements you will not select. In order to specify those elements you need to select the n-k elements that will not be selected. Hence, each time you are selecting k from n, you are also selecting n-k from n, and from that reason both combinatorial numbers are equal.
Answer:
(-3, -7)
Step-by-step explanation:
y = 4x + 5
y = x - 4
add 4 to both sides of the second equation to get y + 4 = x
plug that back into the equation to get y = 4(y + 4) +5
distribute to get y = 4y + 16 + 5
combine like terms y = 4y + 21
subtract 4y on both sides to get -3y = 21
divide both sides by -3 to get y = -7
plug -7 into the second equation to get -7 = x - 4
add 4 on both sides to get -3 = x
therefore (-3, -7)
Here is the answer in comma-separated list.
(5, 10) , (10,15), (15, 20) (20, 25) (25, 300 (30, 35)
You need 5 dimes while having 10 or 25
Answer:
3km
Step-by-step explanation:
d = 2r so r = 1/2 * d = 1/2 * 6 = 3km
