Answer:
When you see a formula like this, try to operate, so you will see some identities sooner or later. In this case, we have a substraction identity:
\frac{cos ( \alpha - \beta )}{cos \alpha cos \beta } = \frac{cos \alpha cos \beta + sin \alpha sin \beta }{cos \alpha cos \beta } = 1 + tan α · tan β
Step-by-step explanation:
Answer:
Step-by-step explanation:
Given
Required
The probability of selecting 2 same colors when the first is not replaced
The total number of ball is:
This is calculated as:
So, we have:
<em>Note that: 1 is subtracted because it is a probability without replacement</em>
Answer:
I belive x=4.9
Step-by-step explanation:
According to the question,
Let,
"n" represent the number of miles semir walked.
"y" represent the number of miles sarah walked.
Now, according to the question,
y = 2n - 5 ........................this is your equation
Also,
the question states, each of them collect $18 in pledges for every miles walked.
Given,
Sarah collected $450
Now,
Using unitary method,
Sarah collects $18 for 1 mile
Sarah collects $1 for (1 / $18) mile
Sarah collects $450 for (1 / 18) * 450 mile
= 25 miles
So, Sarah walks 25 miles.
Now,
Taking equation,
y = 2n - 5
Since, y is the no. of miles sarah walked, we can write 25 in place of "y" So,
(25) = 2n - 5
25 + 5 = 2n
30 = 2n
30 / 2 = n
15 = n
Since, "n" is the no. of miles that semir walked, Semir walked 15 miles.
