Answer:
190 possibilities.
Step-by-step explanation:
The problem is called 20 choose 2, given by the formula for combinations
C(20,2) = 20! / (2! (20-2)!) = 190
alternatively, we can reason it this way:
there are 20 choices to choose a captain and 19 choices for an alternate captain for a total of 380 ways.
However, there are 20 choices to choose an alternate captain and 19 choices for a captain for a total of 380 ways.
Since we are essentially double counting every choice of the posts, we need to divide 380 by 2 to get 190 ways.
Hey there!
To solve this system of equations, you will need to get one of the terms in both equations to cancel out to zero. If there isn't a term that you can cancel out, you can multiply either or both equations to make that term. There's no wrong way to do this, just as long as you make sure that you double check whether your should add or subtract. This is easier shown than explained, so refer below:
<span> x + y = +1
5x + y = –6
</span>–1(x + y = +1)
5x + y = –6
–x – y = –1
5x + y = –6
You can see that once we combine these equations by adding, the y term will become 0, eliminating it. This is necessary for solving the system, so make sure you do it. Also, remember to distribute the term that you need to to all of the numbers in the equation! After that, just solve for the variable that's still in the equation.
–x – y = –1
+ 5x + y = –6
4x + 0y = –7
4x = –7
x = –1.75
Now, just plug the value we found for x into either one of your equations in the original system as it's presented in your problem.
x + y = 1
–1.75 + y = 1
+1.75 +1.75
y = 2.75
All that's left to do is check your point (–1.75, 2.75). If it's true for both equations, your answer is correct!
–1.75 + 2.75 = 1
<span>5(–1.75) + 2.75 = –6
</span>(–1.75, 2.75) is the solution to your system.
Hope this helped you out! :-)
Answer:
x-intercept = 3.6
y-intercept = -1.2
Step-by-step explanation:
156/4=39 miles per gallon. 39*12 gallons is 468 miles, and 6 gallons is 234.
