Choose the expression that represents a quadratic expression.

a. 9x - 2

b. 5x^2 + 9x - 1

c. -2x^3 + 8x^2 - 7x + 1

d. x^4 - 12x^3 + 8x^2 - 7x + 1

Respuesta :

Answer:

b. 5x^2 + 9x - 1

Step-by-step explanation:

A quadratic expression had the highest power of the variable at 2

x^2

b. 5x^2 + 9x - 1

a  has the highest power as x

c and d goes higher than x^2