Question

The equation $\left|\begin{array}{ccc}5& x& 4y\\ 2& -5& -12\\ 1& 0& 3\end{array}\right|=21$ represents a –

• A. A point on xy plane
• B. A straight line
• C. A plane
• D. None of these

Answer 1

The correct option is B

A straight line

You first expand the determinant. What form is it coming out to be? If you expand the determinant you will get a polynomial of the form ax + by + c = 0 which represents a straight line.