# Simplex method in matrix form with the big $M$ method?

If I have one constraint $$3_{x1}+2_{x2}=18$$ in a maximize problem you need to fulfil $$AX\le b$$
what should I do to fit the condition ?
What I think is:
$$3_{x1}+2_{x2}\le 18$$ and
$$3_{x1}+2_{x2}\ge 18$$ becomes $$-3_{x1}-2_{x2}\le -18.$$
In tableau form we can use the big $$M$$ method to fix this but in matrix form this is not quite right.

First thing to know is the number of decision variables and number of constraints involved in your problem. I don't see any reason to split equality equations into two inequalities. One can directly add an artificial variable in the equality constraint $$3x_1+2x_2=18$$ and proceed with Big M or Two Phase method to obtain the solution.