Question

What is 7x sqaured =-21

Answer 1

`7x^2=-21`

we need to clear x

`\begin{gathered} x^2=(-21)/(7) \\ x^2=-3 \end{gathered}`

we can't have a square root of a negative number in real numbers, if we use complex numbers we can obtain the next values for x

`x=\pm i\sqrt[]{3}`