Answer:
First, second, third, and fourth are functions
Step-by-step explanation:
Each input in the first, second, third, and fourth only have one output. In the fifth one 3.3 and 6.6 are seen twice as the x-value, so this is incorrect.
(answered this on your other question, but I will put it here too!)
Cada entrada en la primera, segunda, tercera y cuarta tiene solo una salida. En el quinto, 3.3 y 6.6 se ven dos veces como el valor de x, por lo que esto es incorrecto.
(respondí esto en tu otra pregunta, ¡pero también lo pondré aquí!)
<h3>
Answer: 28</h3>
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Explanation:
Method 1
Imagine a table with 8 rows and 8 columns to represent all possible match-ups. You can actually draw out this table or just think of it as a thought experiment.
There are 8*8 = 64 entries in the table. Along the northwest diagonal, we have each team pair up with itself. This is of course silly and impossible. We cross off this entire diagonal so we drop to 64-8 = 56 entries.
Then notice that the lower left corner is a mirror copy of the upper right corner. A match-up like AB is the same as BA. So we must divide by 2 to get 56/2 = 28 different matches.
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Method 2
There are 8 selections for the first slot, and 8-1 = 7 selections for the second slot. We have 8*7 = 56 permutations and 56/2 = 28 combinations.
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Method 3
Use the nCr combination formula with n = 8 and r = 2

There are 28 combinations possible. Order doesn't matter (eg: match-up AB is the same as match-up BA).
Notice how the (8*7)/2 expression is part of the steps shown above in the nCr formula.
I believe you should try to plug in the ordered pair to see if the solutions work.
The ordered pair is (x,y) because x is on the x-axis and y is on the y-axis, therefore in (16,-3) the x=16 and y=-3.
Now substitute, meaning plug in those numbers into the equation.
For x+2y=10 would be 16+2(-3)=10
Now you just need to solve one side and see if it equals the other side.
16+2(-3)
First you use order of operations to solve this. PEMDAS. So you multiply 2(-3) first because of the parenthesis and it being multiplication.
16+(-6) and when you have a positive number adding a negative number it’s going backwards of the number line, basically meaning subtraction in a way. Sorry if this confuses you, if you already know how to do negatives and such nevermind this part.
But 16+(-6)=10
So now you look at both side of the equation, does the left side equal to the right? 10=10, so yes. It is a solution for that equation.
Now for the next equation, 7y=-21
Again, plug in the ordered pair (16,-3) into the equation. Remember that it’s (x,y).
There is no x in this equation so no need to worry about that; you only plug in y for this one.
7(-3) Now you multiply. Whenever you multiply a positive number and a negative number, the answer will always be negative. So 7(-3) is -21.
Now look if the left side is equivalent to the right. Does -21=-21? Yes. The ordered pair is a solution.
(16,-3) is a solution to both equations.
Hope this helps!
Answer: 121 mph
Step-by-step explanation: First, I did 6 x 7, and I got 42. Then I did 42 + 79, and I got 121 mph as my answer.
H + c = 456
c = 3h
h + 3h = 456
4h = 456
h = 456/4
h = 114 <=== hamburgers sold
c = 3h
c = 3(114)
c = 342......cheeseburgers sold