Final answer:
The step that should follow Gaussian elimination in solving a system of linear equations is substitution (A).
Step-by-step explanation:
The step that should follow Gaussian elimination in solving a system of linear equations is substitution. Gaussian elimination is a method used to transform the system of equations into row echelon form or reduced row echelon form. Once this is done, substitution can be used to solve for the unknown variables by back-substituting the values obtained from Gaussian elimination into the original equations.
After performing Gaussian elimination on a system of linear equations, the step that should follow is substitution. Gaussian elimination is used to put the system in either echelon form or reduced echelon form, making it easier to solve for the unknowns. Once the system is in one of these forms, you can back-substitute to find the values of the variables. This method does not require factoring, differentiation, or integration, as those are techniques used in other types of mathematical problems.
So, the answer is A.