1. Solve the following system of 4 equations with 4 unknowns by hand.
x1 + x3 = 25 x2 + x3 = 18 x1 + x2 = 23 x3 + x4 = 15
2. Write the system in the previous problem in matrix form and solve it.
Courses
|
|
1
|
2
|
3
|
|
1
|
82
|
95
|
80
|
|
2
|
89
|
92
|
97
|
|
Students 3
|
65
|
68
|
60
|
|
4
|
75
|
79
|
64
|
|
5
|
85
|
72
|
70
|