Question

Identify which of the following is/are linear equation(s) in two variables.
A.) $2^{2}x+y+1=0$
B.) $x+5y^2+2=0$
C.) $5^{2}x+2^{2}y+3^2=0$

Answer 1

A.) $\left(2^2\right)x+y+1=0$, is a linear equation in two variables because the highest power of this equation is 1.
B.) $x+5\left(y^2\right)+2=0$, is not a linear equation because highest power of this equation is 2. So this is a quadratic equation.
C.) $\left(5^2\right)x+\left(2^2\right)y+\left(3^2\right)=0$, is a linear equation in two variables because it has the highest power of 1 and variables x and y.