Doubt in Quantitative comparison

Which one out of the two is greater?

Quantity A) x^2-10x+28

Quantity B) 2

I have seen a solution wherein they try to make a perfect square by subtracting 3 from both sides. But do we really have to do that? Isn’t there any other way out?

Can you please provide the steps to how will you approach it? Doesn’t matter if its a wrong approach, just write how you attempted it!

Well, without giving it any second thought, I immediately applied the formula (-b±√b^2-4ac/2a)
According to that, I’m getting no real roots of this equation and hence, I chose the answer as D.

How does finding the roots help you? All you found out is that the graph never touches the x-axis.

So in such questions, we need to manipulate the quantities given?

Yes; specifically, do so for Quantity A.

Got it, thanks