Identify which equation is a quadratic equation.

y = 3x + 4

y + x2 = (x − 2)(x + 7)

y = −4x(x − 4) + 2x

y + 3 = (x + 12)(x2 + 2)

Question

Identify which equation is a quadratic equation.

y = 3x + 4

y + x2 = (x − 2)(x + 7)

y = −4x(x − 4) + 2x

y + 3 = (x + 12)(x2 + 2)

anonymous · Answer

quadratic is a equation in which highest power of x is 2 so simplify each and see which equation has highest power of x 2

anonymous · Answer

this is like the twelfth time i have seen this exact same rather silly problem
where does it come from?

anonymous · Answer

if you multiply this $$y = −4x(x − 4) + 2x$$ out, you will get a quadratic

anonymous · Answer

this one $y = 3x + 4$ is linear,there is no square

anonymous · Answer

Okay, thank you! :)

anonymous · Answer

this one $y + x^2 = (x − 2)(x + 7) $ looks like it could be a quadratic, but is isn't because the $x^2$ term on both sides will cancel

anonymous · Answer

this one $y + 3 = (x + 12)(x^2 + 2)
$  if you multiply out you will get an $x^3$ term, so not quadratic

anonymous · Answer

i'd still like to know where this silly question comes from and why everyone seems to have it