You divide 3 on both sides then you equation is the square root of -4x-4 =4 and you square the number on both sides because u need to do the same things on both sides and you get -4x-4=16 subtract by 4 on boyh sides to get -4x=20 and divide by -4 on both aises to get x=-5
I hope this helped i know this explanation is a bit wonky