Question

Which equation is a quadratic equation?  
3x − y = 8x + 2
y = 7x(5 − 2x) + 9
7x2 + y = (3 + x)(7x − 1)
y − 3 = (x2 − 3)(8x + 3)

Answer 1

Is the question which one is NOT a quadratic equatoin ?
only the 1st one isn't. The 1st one is a linear equation.

Answer 2

It's which one is a quadratic equation... How do you figure out if it is one?

Answer 3

A quadratic equation will be equivalent to this:
y=ax^2+bx+c
The highest power of x will be 2 ( x^2 )

Answer 4

Oh, okay... Thanks! :) I'll try and figure this one out then... :P

Answer 5

wait the last one isnt quadratic

Answer 6

oh, ok. :)

Answer 7

Is this it ?
y − 3 = (x^2 − 3)(8x + 3)

If so:
y = 8x^3 + 3x^2 - 24x -9 +3
y = 8x^3 + 3x^2 - 24x -6

The highest power of x above is 3 , so it's not a quadratic equation

Answer 8

are you supposed to pick only one correct answer ,
or can you pick more than one answer ?

Answer 9

Only one. :)

Answer 10

make sure all the options in the question are written out correctly then.
can you click the "Draw" tool below, and write the options there ?