Please answer this

Dear Student

An equation is said to be linear equation in two variable if  it is written in the form of ax + by + c = 0, where a, b and c are real numbers and the coefficients of x and y, i.e. a and b respectively are not equal to 0.

Checking Options 

Option (a) 2x = 3 

2x + 0.y - 3 = 0 

Since, it is in form of ax + by + c = 0, so it is linear equation in two variable.

Option (b) x^2 + x = 1

x^2 + x - 1 = 0 

Since, it is not in form of ax + by + c = 0, so it is not a linear equation in two variable.

Option (c) 4 = 5x - 4y 

5x - 4y - 4 = 0

Since, it is in form of ax + by + c = 0, so it is linear equation in two variable.

Option (d) x - √2y = 3 

x - √2y - 3 = 0

Since, it is in form of ax + by + c = 0 , so it is linear equation in two variable.

Hence, option (b) is correct.

Regards