Answer:
43,680 ways.
Step-by-step explanation:
We have been given that an experiment involves 16 participants. From these, a group of 4 participants is to be tested under a special condition. We are asked to find the number of groups of 4 participants that can be chosen, assuming that the order in which the participants are chosen is irrelevant.
We will use permutations formula to solve our given problem.
For our given problem 
and 
.
Therefore, 4 participants can be chosen in 43,680 different ways.
Step-by-step explanation:
multiplying the 2nd eqn by 9 we get,
9x+9y=81
then,subtracting 1st and 2nd eqn
9x+5y=41
9x+9y=81
- - -
__________
0. -4y=-40
we get y = 10
then we get x=9-y
x=9-10
x= -1
so x is -1 and y is 10
Answer:
2070
Step-by-step explanation:
23x90=2070
10x23=230
230x9=2070
please mark brainliest
Answer
-8 
r > 0
Step-by-step explanation:
you know that r is less than or equal to -8, so you write that, and then you know that r is also greater than 0, so then you add that to it, and then you have the answer. r will be in the middle because it is the range of what are can be.
Answer:
0.65 grams
Step-by-step explanation:
0.42 + 0.23 = 0.65
