Question

Check whether $(x+3{)}^3=x^3-8$ is a quadratic equation?.

Answer 1

We have,

${\left(x+3\right)}^3=x^3-8$

$x^3+{\left(3\right)}^3+3\times x^2\times 3+3\times x\times 3^2=x^3-8$

$x^3+27+9x^2+27x=x^3-8$

$9x^2+27x+27+8=0$

$9x^2+27x+35=0$

Yes, it is a quadratic equation.