There is no need t do anything particular.
An algebraic equation.
An open sentence.
A = b.
Yes.
Squared means to the power 2. An wxample would be x2 = 25.
An algebraic equation.
A bivariate equation.
Multivariable equation
Multivariable equation
that's an equation.
An open sentence.
It is an equation. It could be an algebraic equation, or a trigonometric equation, a differential equation or whatever, but it is still an equation.
Literal Equation
A = b.
No. In the variable x, alone, it is linear. In the variable y, alone, it is linear. But taken together, in x and y, you have a term which contains xy - that is, a term in which the powers of the unknowns add to 2. So the equation is not linear.
An algebraic expression is an expression or and equation that contains at least 1 variable
add one to the problem