An open sentence.
A = b.
Yes.
The word linear means in a straight line. If the graph is a line, it is linear. Also, linear equations are of the first order; they contain a variable but not a square (or higher power) of a variable. If the equation contains x2 it is not linear.
Squared means to the power 2. An wxample would be x2 = 25.
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.
An algebraic expression is an expression or and equation that contains at least 1 variable
add one to the problem
Domain is the independent variable in an equation. It is what you put "in" the equation to get the Range.
I'm pretty sure it's an open sentence.