The number of distinct real roots of the equation $$|x+1||x+3|-4|x+2|+5=0$$, is _______

Let $$x_1, x_2, x_3, x_4$$ be the solution of the equation $$4 x^4+8 x^3-17 x^2-12 x+9=0$$ and $$\left(4+x_1^2\right)\left(4+x_2^2\right)\left(4+x_3^2\right)\left(4+x_4^2\right)=\frac{125}{16} m$$. Then the value of $$m$$ is _________.

The number of real solutions of the equation $$x|x+5|+2|x+7|-2=0$$ is __________.

The number of distinct real roots of the equation $$|x||x+2|-5|x+1|-1=0$$ is __________.