A linear equation has maximum power of a variable(variables) 1.
In order to find the linear equations we need to check the equations with variable with power one.
Also the variable should be in numerator only.
Let us check option one by one:
a-y=√x + 1 we have a radical on x.
Therefore, it's not a linear equation.
b-y=1/x
We have x in the denominator of 1.
Therefore, it's not a linear equation.
c-y=x^2 +4
We have power 2 of x. Therefore, it's not a linear equation.
d-y = -2/3x + 4/3.
We have x and y powers only 1.
Therefore, it's the only linear equation.
