Question 31435
6y^2 + y = 12

6y^2 + y - 12 = 0 

Here you must know how we make factors i.e. splitting of the middle term...if you might not knew then contact me again and I will explain to you)... 

6y^2 + (9-8)y - 12 = 0 

opening brackets would give ,,, 

6y^2 + 9y - 8y - 12 = 0 

taking common from first two i.e. 6y^2 + 9y and last two i.e. - 8y - 12 variables...we get 

3y(2y+3) - 4(2y+3) = 0

(3y-4)(2y+3)= 0

so either y = 4/3

or y = -3/2

hope this will help you 
Please feel free to revert back for any further queries.