My question goes like this
If 5a+4b+20c=t, then what is the value of t for which the line ax+by+c-1=0 always passes through a fixed point?
I tried but couldn't solve it so I looked at the solution. The solution says that the equation has 2 independent parameters. I get that. If we choose a and b, c automatically gets defined. Hence c is not really independent.
In the next line it says that it can pass through a fixed point if there is only one independent parameters. This is where I got stuck. I tried a lot but can't understand their logic.
Then they defined a relation between a/(c-1) and b/(c-1) to get the answer which is t=20.
Please help me because I feel understanding this would really clear my concepts and may prove very beneficial later.