Permutation: In a race of 10 students, find the number of ways students can finish 1st, 2nd, and 3rd. In this case the order matters, so it is a permutation.
10 x 9 x 8 = 720 ways
Combination: In a class of 10 students, find the number of ways a group of 3 students can be selected to win a prize. In this case the order doesn't matter, so it's a combination.
10 x 9 x 8 / (3 x 2 x 1) = 120 ways
The answer to your question is 16 and 5/12
x = 5i x =-5i
Step-by-step explanation:
x^2+25=0
Rewriting
x^2 - (-25)=0
Writing as the difference of squares
a^2 - b^2= (a-b) (a+b)
where a = x and b = (sqrt(-25)) =±5i
( x-5i) ( x+5i) =0
Using the zero product property
x-5i =0 x+5i =0
x = 5i x =-5i
Answer:
90 hardcover books
Step-by-step explanation:
We can solve this by setting up a couple of equations.
Let's allow x to represent the number of paperbacks Tim owns, and allow y to represent the number of hardcover books he owns.
Using the information in the question, we can write the equations:
1)x = 4y-3
2) x+y=447
Let's rearrange equation 1 so that it is in standard form:
x-4y=-3
And then let's multiply equation 2 by 4 so that we can cancel out y when we solve the system of equations:
4(x+y=447)
4x+4y=1,788
Then we can add the two equations and solve for x:
1) x-4y=-3
+ 2)4x+4y=1,788
------------------------------------
5x=1,785
x=357
So now we now the number of paperback books Tim has is 357. Let's plug this into one of the original equations to solve for the number of hardcover books (y):
357+y=447
y=90
And now we know that Tim owns 90 hardcover books.
Answer:
AB = 6.4
Step-by-step explanation:
Assuming that AB + BC is AC, then we can say the following:
AB + BC = AC
AB + 6.8 = 13.2
AB + 6.8 + -6.8 = 13.2 + -6.8
AB = 6.4
Cheers.
