The quadratic formula is...

your a will be in front of your x^2, b in front of your x, and c will be the number without an x. Plug those into the equation and you'll get two answers. That will be it
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!
The answer will be 35 because it is a proportional side length
Your answer is 7.
I subtracted 5 from 12 to find the missing number for KL that is 7.
Therefore, your answer is 7