Question

Identify which of the following equations is a Quadratic Equation.

• A. $5x+8=0$
• B. $-2x^2+x=21$
• C. $ax+by+c=0$
• D. None of these.

Answer 1

The correct option is B $-2x^2+x=21$

Only option b is an equation where there is only one variable x and whose degree is 2. Thus it is a quadratic equation.Hence option b is the correct answer.