A quadratic equation is one in which the highest exponent of x is 2. [tex]7x^2+14x=0[/tex] is quadratic; the highest exponent is 2. x³-3x²+1=0 is NOT quadratic. The highest exponent of x is 3, not 2. 5x-7=0 is NOT quadratic. The highest exponent of x is 1, not 2. x²+3x-5=0 is quadratic; the highest exponent of x is 2. x-5=9x+7 is NOT quadratic. The highest exponent of x is 1, not 2. x²-x=3x+7 is quadratic; the highest exponent of x is 2.
