Please help with the following question :))

Matrix A from Problem 5 (4x4): -30 12 49 6 -30 21 34 -5 -20 10 30 -10 5 11 Vector b from Problem 5 (length 4 col.): 75 65 32 68Problem 5 [12 marks]: Let A be the ( 4 x4)-matrix displayed in cells G20-J23 of the Excel spreadsheet. Moreover, Let to be the length 4 column vector displayed in cells 627-630. Use Cramer's Rule to com- pute the third entry x3 of the unique solution x= is of the matrix equation Ax = b xu