The number of real roots of $|x|^2-5|x|+6=0$ is

The number of real solutions of the equation $x(x^2+3|x|+5|x-1|+6|x-2|)=0$ is

The number of all common roots of the equation $x^4-10x^3+37x^2-60x+36=0$ and the transformed equation obtained by increasing any two distinct roots of it by $1$,keeping the other two roots fixed,is

If $P(x)=ax^{2}+bx+c$ and $Q(x)=-ax^{2}+dx+c$, where $ac \neq 0$ ($a, b, c, d$ are all real), then $P(x) \cdot Q(x)=0$ has

The sum of all the real roots of the equation $(e^{2x} - 4)(6e^{2x} - 5e^x + 1) = 0$ is

The product of the roots of the equation $9x^{2}-18|x|+5=0$ is