Assignment:
Determine which of the following are linear equations and which are not linear equations. State the reason for your answer.
(a) x + y = 1000
(b) 3xy + 2y + 15z - 20 = 0
(c) 2xy + 4yz = 8
(d) 2x + 3y 4z = 6.
Provide complete and step by step solution for the question and show calculations and use formulas.