Question

Which of the following equations is quadratic?

x(x2 + 1) = 0
5(4x + 2) = 3
(x + 3)(x + 4) = 5

Help fast is quiz

Answer 1

(x+3)(x+4)=5 is a quadratic equation

Answer 2

1) X(x²+1)=0

x³+X=0
so it's not a quadratic equation because X to the power is three

2) 5(4x+2)=3

20x+10-3=0
20x+7=0
it's not a quadratic equation because X to the power is 1 and x²=0

3) (X+3)(X+4)=5

x²+4x+3x+12-5=0
x²+7x+7=0

so it's a quadratic equation because it is in the form of ax²+bx+c=0