In the equation a b and c are constants and x is a variable. You are expected to translate what is given in words in the question into algebraic expressions and equations and solve them to arrive at the answer. Khan Academy is a 501c3 nonprofit organization.
1 Linear Equations.
Put in a b and c. This is the set of coordinates satisfying the equation fa b 0. In the equation a b and c are constants and x is a variable. If fis of the form ax by ca linear function then the set Zcuts out a line or a point or a subspace.