The number of distinct real roots of the equation |x+1||x+3|-4|x+2|+5=0 is ________. [2024]
(2)
|x+1||x+3|-4|x+2|+5=0
(I) If x<-3, x2+4x+3+4x+8+5=0
⇒x2+8x+16=0⇒x=-4 (one solution)
(II) If -3≤x<-2, -x2-4x-3+4x+8+5=0
⇒x2-10=0⇒x=±10
which do not satisfy -3≤x<-2
(III) If -2≤x<-1, -x2-4x-3-4x-8+5=0
⇒x2+8x+6=0⇒(x+4)2=10
⇒x=-4±10 which do not satisfy -2≤x<-1
(IV) If x≥-1, x2+4x+3-4x-8+5=0
⇒x2=0⇒x=0 (one solution)
Hence, the number of distinct real roots are two.