$0x+0y+c-0$ is not a linear equation?

If an equation is written in the form $ax+by+c-0$ 

Here, the equation is  $0x+0y+c=0$, where a = 0 and b = 0.

As per the definition, we know that the values of a and b shouldn't be zero at the same time.

Thus, $0x+0y+c=0$ is not a linear equation.

Hence, the given statement is true.