Question

If we have a linear equation what is the power of the variable(s) involved

Answer 1

The linear equation is an equation that may be put in the form

$a_1x_1+a_2x_2+\ldots+a_nx_n + c = 0,$ where $a_1,\ldots, a_n, c$ are constants.

So every variable $x_1, \ldots, x_n$ should be in power less or equal to 1. Every involved in the equation variable should be in power 1.

For example, $2x + \sqrt7\cdot y - 1.13 z+ 6 = 0$ is a linear equation, but $2x^2 - 1= 0$ is not linear.