Question

Which of the equations $x+9y=7, x^2+5y=0,$ and $y=3x-1$ is not linear?

Short answer

The equation $x^2+5y=0$ is not a linear equation.

Step-by-step solution

– Definition of a linear equation.

In a linear equation the exponent of each variable is 1 and the variables may not be multiplied together. The graph of a linear equation is always a line.

– Given information.

The given equations are:

$\begin{array}{c}x+9y=7\\ x^2+5y=0\\ y=3x-1\end{array}$

– Check whether the equations are linear or not.

In the equation $x+9y=7$ the exponent of x is 1 and the exponent of y is 1. So, this equation is linear equation.

In the equation $x^2+5y=0$ the exponent of x is 2 and the exponent of y is 1. So, this equation is not a linear equation because x has an exponent other than 1.

In the equation $y=3x-1$the exponent of x is 1 and the exponent of y is 1. So, this equation is linear equation.

Thus, the equation $x^2+5y=0$ is not a linear equation.