Question

Which equation is a quadratic equation?

A.) 3x − y = 8x + 2

B.)y = 7x(5 − 2x) + 9

C.) 7x2 + y = (3 + x)(7x − 1)

D.) y − 3 = (x2 − 3)(8x + 3)

Answer 1

a quadratic eqn is a second degree polynomial with a single variable. which can be genarally expressed as,
\[ax^{2}+bx+c=0\text{ where a,b,c are constants and }a\neq0\]
can u do it now?

Answer 2

try and tel me ur answer

Answer 3

okay

Answer 4

im confused?

Answer 5

is it C..?

Answer 6

is y in this problem is a constant o not?

Answer 7

@zakiaboo if y is not a constant.. theres a little problem..

Answer 8

umm i think so.

Answer 9

C has other issues with it other than a y

Answer 10

@zakiaboo try using what @Neo92 said
ax^2+bx+c=0
if you put some of your answers in to that form it may help you figure it out.

Answer 11

7x2 + y = (3 + x)(7x − 1)

7x2 + y = 7x^2 + (other stuff)

since both sides contain 7x^2, its not really there .....

7x2 + y = 7x^2 + (other stuff)
-7x^2 -7x^2
-----------------------
y = (other stuff)

Answer 12

@amistre64 yep.. it got no terms of 2nd order

Answer 13

oh you mean put it in the order that its suppose to be in..?

Answer 14

C turns out to be a trick that they are playing on you; it LOOKS quadratic, but its really linear

Answer 15

yea i just figured out its B.

Answer 16

right?

Answer 17

b is good

Answer 18

y = 7x(5 − 2x) + 9

y = 14x^2 + .....

Answer 19

yay for B

Answer 20

B.
http://www.mathway.com/answer.aspx?p=prec?p=ySMB15SMB01SMB157x(5SMB15%E2%88%92SMB152x)SMB15+SMB159SMB15?p=1?p=?p=?p=?p=?p=0?p=?p=0?p=?p=?p=SolveSMB15theSMB15EquationSMB15forSMB15y

D.
http://www.mathway.com/answer.aspx?p=prec?p=SMB15ySMB15%E2%88%92SMB153SMB15SMB01SMB15(x2SMB15%E2%88%92SMB153)(8xSMB15+SMB153)?p=1?p=?p=?p=?p=?p=0?p=?p=0?p=?p=?p=SolveSMB15theSMB15EquationSMB15forSMB15y