Respuesta :
Answer:
There are 15 purple marbles.
Step-by-step explanation:
Given:
A bag contains purple marbles and red marbles, 27 in total.
The number of purple marbles is 9 less than 2 times the number of red marbles.
Now, to find the number of purple marbles.
Let the number of red marbles be [tex]x.[/tex]
And the number of purple marbles be [tex]2x-9.[/tex]
Total marbles = 27.
According to question:
[tex]x+(2x-9)=27.[/tex]
⇒ [tex]x+2x-9=27.[/tex]
⇒ [tex]3x-9=27.[/tex]
Adding both sides by 9 we get:
⇒ [tex]3x=36.[/tex]
Dividing both sides by 3 we get:
⇒ [tex]x=12.[/tex]
So, to get the number of purple marbles we put the value of [tex]x[/tex]:
[tex]Purple\ marbles =2x-9[/tex]
[tex]Purple\ marbles =2\times 12-9[/tex]
[tex]Purple\ marbles =24-9[/tex]
[tex]Purple\ marbles =15.[/tex]
Therefore, there are 15 purple marbles.
