Chapter 4 Quadratic Functions and Factoring - 4.6 Perform Operations with Complex Numbers - 4.6 Exercises - Skill Practice - Page 279: 8

$$y = \pm2\sqrt3i$$

For imaginary numbers, we know that standard form is $a\pm bi$, where $a$ is the real part and $b$ is the imaginary part. To get the expression into this form, we combine like terms like we did with polynomials. Doing this, we find: $$-4y^2=48 \\ y^2=-12 \\ y=\sqrt{-12} \\ y = \pm2\sqrt3i$$