HELP PLEASE BEST ANSWER GETS THE MEDAL............................................................................

Which equation is a quadratic equation?

y + 7 = −3x(4 − x) + 9x

y = −2x + 5

y + 2x3 = (2x − 2)(x + 5)

y − 9x = (x2 + 1)(5x − 1) + 3

Question

HELP PLEASE BEST ANSWER GETS THE MEDAL............................................................................   







Which equation is a quadratic equation?

 y + 7 = −3x(4 − x) + 9x

 y = −2x + 5

 y + 2x3 = (2x − 2)(x + 5)

 y − 9x = (x2 + 1)(5x − 1) + 3

anonymous · Answer

http://www.math.com/students/calculators/source/quadratic.htm

anonymous · Answer

thanks

anonymous · Answer

y + 7 = −3x(4 − x) + 9x
y=-12x+3(x^2)+9x-7
y=3x^2-3x-7
so because of x^2 it's quadratic equation