Which one is an example for; standard linear equation?

1. $ax+b=0$
2. $ax^{2}+b x+c=0 $
3. $ a x^{3}+b x^{2}+c x+d=0$
4. $ a x^{4}+b x^{3}+c x^{2}+d x+e=0 $

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Given :

The set of equations are given.

To find :

We have to find the standard linear equation among the given equations.

Solution :

Linear equation:

A linear equation is an equation of a straight line. The power of the variables should be 1. Linear equations in one variable may take the form $ax + b = c$ and are solved using basic algebraic operations.

For example, $2x+3=8$ is a linear equation having a single variable in it.

Among the given options only $ax+b = 0$ has a degree of 1.

Therefore, A is the correct option.