Hi there!
First we need to remember the following.

Now substitute both of the formulas.

Work out the parenthesis.

And finally collect terms.

~ Hope this helps you!
-18 + x = -11
Let's add 18 to both sides
x = 7
Answer:
3,-7
Step-by-step explanation:
So this is what's known as a combination. a combination is a group where the order does not matter. to solve a combination, you use this equation:
n! / (r! *(n-r)!)
n is the total number of objects being sorted (8)
r is the group you need to sort them into (4)
(i know it's 2 groups of 4 but if you solve this for 1 group, the other group is automatically made of the remaining kids)
definition of !:
a number with a ! means 1*2*3...*that number (so that number multiplied by every number smaller than it all the way to one)
so we put 8 and 4 in this equation:
8! / (4! *(8-4)!)
simplify:
8! / *(4! 4!)
multiply out:
(8*7*6*5*4*3*2*1) / (4*3*2*1 * 4*3*2*1)
and put that in your calculator
you will get 70
your answer is 70
To test for a triangle, the two smallest sides added together have to be greater than the third side.
3.95 + 4.56 > 8.65
8.51 > 8.65
this is false
4.56 + 8.65 > 10.31
13.21 > 10.31
could be it
4.56 + 8.65 > 13.21
13.21 > 13.21
no, this would mean they're equal
4.56 + 8.65 > 20.25
13.21 > 20.25
this is also false
<span>B. 10.31 cm
</span>