please help..

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

please help..

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

@justuu

anonymous · Answer

Try to write out each equation in y=ax^2+bx+c form. Only one will work and that is your answer.

anonymous · Answer

what?

anonymous · Answer

You need an equation that will satisfy the form:$$ax ^{2}+bx+c=0$$
where a,b,c are integers

anonymous · Answer

Use algebra for all of the given equations, and see which one can be arranged in the form mentioned above.

anonymous · Answer

hu? im new to this site... i just need someone to help explain it. but break it down and explain in peices i missed this whole lesson i was sick

anonymous · Answer

If you want to use the easiest method to find the quadratic equation, Look for the answer with the highest order term being $$x ^{2}$$ multiplied by some coefficient.