Question

Identify which equation is a quadratic equation.
Answer

y = -6x - 3

y + x2 = (x - 1)(x + 7)

y - 9 = (x - 1)(x2 + 4)

y = 5x(x + 3) - 8

Answer 1

last one

Answer 2

quadratic equation means you need to have term x^2 somewhere in your equations...so the first one isn't...it's linear because you have only x=x^1...if you do some addition and multiplication you'll see x^2 will disappear, the third is cubic equation, because when you multiply you'll get term x^3 and finally the last equation is y=5x^2+15x-8...so you see you have x^2 in your equation so the answer is clear :D

Answer 3

@abhijitjain1995 you aren't supposed to just give the answer haha You are expected to explain how/why you got what you did.

Answer 4

@rebeccaskell94 oh really . wait haha

Answer 5

yeah lol It's a big deal for the site ;D

Answer 6

@rebeccaskell94 try, try and then cry lol

Answer 7

I never cry o.o

Answer 8

1st one index for x is one . 2nd one involves 2 different variables/ 3rd one is the ritey - index of x is 2.last one is a cubic one .

Answer 9

oh inter change the last two . my mistake

Answer 10

Thanks everyone I'd give you all medals but I cant so I will fan you all

Answer 11

tennis - thanks mate

Answer 12

yw