This is 6C2
= 6!
-------- = 6*5 / 2*1 = 15
2! 4!
Answer:
m - 18
Step-by-step explanation:
Symbolically, that difference would be written as m - 18.
So discriminant gives us 3 possibilites connected with result of the equation b^2-4ac. If it is bigger than zero, there are 2 solutions, if answer is exactly 0, then there is one answer and if the number is lower than 0, there are no solutions.
Discriminant of your quadratic equation is (-4)^2-4*1*5=16-20=-4, so there are no solutions.