Question

Which of the following is a linear equation in one variable?

• A. $2x+3$
• B. $2x^2=3$
• C. $2x+3=0$
• D. $3x^2=5$

Answer 1

The correct option is C $2x+3=0$

An equation which has only one variable and the highest power of that variable is one is termed as a linear equation in one variable.

$(2x+3)$
is not an equation as it does not have an equality sign in it.

The highest power of $x$ in $(2x^2=3)$ and $(3x^2=5)$ is 2, so it is not a linear equation.

The highest power of $x$ in $2x+3=0$ is 1 and it has an equality sign, hence it is a linear equation in one variable.