Answer:
12
Step-by-step explanation:
5 : 6 = Number of boys to girls
(We have to ×2 to get from 5 to 10 so we must ×2 from 6 to 12)
10 : ? = Number of Boys to girls
10 : 12 = Number of Boys to girls
Let's subtract then: 3x2 - 2x + 3 - (6x2 - 4x + 3)
taking out of the bracket with a changed sign: (there is a minus in front of the bracket)
3x2 - 2x + 3 - 6x2 + 4x - 3
let's reshuffle them so that similar terms are together:
3x2 - 6x2 - 2x + 4x + 3 - 3
Adding up similar terms:
-3x2 + 2x - that's our option 2!
Maybe 11x? i dont really know, thats all the info we get