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)

Answer 1

Is it the first one @aamirfaisalansari ?

Answer 2

only third it can be easily obtained by solving:
1) open the bracket means multiply one to another
2)then bring all x variable to the right hand side
by looking at the highest power say if it is two or not
plz try it

Answer 3

Okay I got it, thanks for your time.