Hey there! I'm happy to help!
If the number of red marbles is 6 more than double the number of black marbles, we can create this equation, with r representing the red marbles and b representing the black marbles.
r=2b+6
We also know that r+b=33, and if we know that r is equal to 2b+6, we can just replace r with that and then solve for b.
2b+6+b=33
We combine like terms.
3b+6=33
We subtract six from both sides.
3b=27
We divide both sides by 3.
b=9
Now we just subtract 9 from 33 to see how many red ones there are.
33-9=24
So, there are 24 red marbles and 9 black marbles.
Now, let's see which of these options are correct.
The equation r+b=33 represents the total number of marbles.
This is true because r plus b is equal to the total, which is 33.
The equation r=2b+6 can be used to find the number of red marbles.
This is true because it we used this r-value to find how many black marbles there were.
The equation r=2b+6 represents the total number of marbles.
This is false because it does not have the total number, which is 33.
The equation r=b=33 can be used to find the number of red marbles.
This is true because we plugged in the r-value to solve for b with this equation.
There are 9 red marbles in the bag.
This is false. There are 24 red marbles.
There are 9 black marbles in the bag.
This is true.
There are 24 black marbles in the bag.
This is false. There are 9 black marbles.
There are 24 red marbles in the bag.
This is true.
Have a wonderful day! :D