### Linear Equations

goals
For what value(s) of $a$, do the pair of linear equations $x + (a^2-3a+3)y = a^2$ and $x + y = 1$ have:
The path of a train A is given by the equation $x+2y-4=0$ and the path of another train B is given by the equation $2x+4y-12=0$. will train A and train B at any point?
If $\dfrac {m+n}{m+3n}=\dfrac {2}{3}$, find: $\dfrac {60n^{2}}{3m^{2}+mn}$.
$4x=x-6$ Find the value of$x$.
Which of the following is not a linear equation in one variable ? why?
$2x-1=\dfrac{3}{2}$
$x+3y=5$
$a=0$