I don't know which quadratic equations you have learned. you can choose the quadratic formula: x= -b +- square root of D divided by 2 times a. There is also factoring or solving by undoing.
2/6 is also equal to 1/3. so if you multiply 69 by (1/3) it equals 23. giving you 23 kit kats.
x= 4. 225 is 15 times bigger than 15. so if you divide 60 by 15 it gives you your answer of 4.