What is Gaussian Elimination with backward substitutions?

What is Gaussian Elimination with backward substitutions?

What is Gaussian Elimination with backward substitutions?
Explain your answer using your own example with MATLAB. Create a 3×3 matrix by using the following command in MATLAB:
>>d = rand(3,3)
After explaining the Gaussian elimination, solve your matrix equation using section 6.3:
x = inv(A) * B
or
x = A\B
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