Simple doubt

[gloomy shell]

Im not really sure how to respond this, i cant remember well.
I have to find if it has no solutions, one solution or two, but i don’t remember how to find them.

[visual cove]

divide both side by -4 it becomes x^2=16 take square root of both sides x= ±4

[gloomy shell]

Thank you!

[grizzled blaze]

.solved