Question 1083141
The easiest way is to set one variable equal to 0 and solve for the other.  This works well when the coefficients are factors of the constant (6 and 5 are factors of 30)
x---------y
0======-6
5---------0
There are other values one may use, but two points determine a line.
{{{graph(300,300,-10,10,-10,10,(6x/5)-6)}}}