10 is the answer.
You know that there are 4 numbers and you have to add the numbers then divide them by four to get the mean. So all you have to do is reverse the steps, multiply 30 by 4 to get 120, then add 12+50+48 to get 110. Then subtract, 120-110=10. To check if it is correct add 12, 50, 48, and 10 to get 120, then divide by 4 to get 30. And voila, there is the answer. I hope this helped for future problems like this one.
Idk ...................... :(
Y = number of yellow marbles
r = number of red marbles
The total number of marbles
y+r=61
The number of yellow marbles compared to red.
y=2r+4
Substitute the second equation into the first equation because they are the same variable and, therefore, are the same number.
2r+4+r=61
Simplify
3r+4=61
Subtract 4 from both sides
3r=57
Divide both sides by three
r=19
We have the number of red marbles, but we are looking for the number of yellow marbles, so plug the 19 red marbles into either equation.
y=2(19)+4
or
y+19=61
Simplify
y=42
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Answer:
42 yellow marbles
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Equations:
y+r=61
y=2r+4
Answer:
The right answer is A.
As a result of it being raised to a negative number, you write its inverse.
The property shown there is the distributive property.
It states that a(b + c) = ab + ac
Or a(b - c) = ab - ac