Rewrite the equation by completing the square 3+x=x^2+3x

the completed square is x=1, -3

The absolute value bars || means that whatever is in side turns to positive so the first one cannot be true

then next 2 are similar, only the last is different

if we try to solve the last 3 then we will get
-6-2x=8 and -6-2x=8, 2 solutions
5x+10=10 and 5x+10, 2 solutions

-6x+3=0 , only one solution becasue you cannot make 0 neagative

the answer is |-6x+3|=0