Question #43136

Solve the following systems of equations using both the matrix left divison and the inverse matrix methods:

(a) -2x1 + x2 = -3

x1 + x2 = 3

(b) 10x1 - 7x2 + 0x3 = 7

-3x1 + 2x2 + 6x3 = 4

5x1 + x2 + 5x3 = 6

(c) x1+ 4x2 - X3 + X4 = 2

2x1+ 7x2 +x3 -2x4 = 16

x1 + 4x2 - x3 + 2x4 = -15

3x1 - 10x2 -2x3 + 5x4 = -15

(a) -2x1 + x2 = -3

x1 + x2 = 3

(b) 10x1 - 7x2 + 0x3 = 7

-3x1 + 2x2 + 6x3 = 4

5x1 + x2 + 5x3 = 6

(c) x1+ 4x2 - X3 + X4 = 2

2x1+ 7x2 +x3 -2x4 = 16

x1 + 4x2 - x3 + 2x4 = -15

3x1 - 10x2 -2x3 + 5x4 = -15

Expert's answer

b1 = [-3;3];

A1 = [-2 1; 1 1];

x1 = A1\b1

b2=[7; 4; 6];

A2=[10 -1 0;-3 2 6; 5 1 5];

x2=A2\b2

b3=[-2; 16; -15; -15];

A3=[1 4 -1 1;2 7 1 -2; 1 4 -1 2; 3 -10 -2 5];

x3=A3\b3

x1 =

2

1

x2 =

-2.4000

-31.0000

9.8000

x3 =

5.0154

-1.2769

-11.0923

-13.0000

A1 = [-2 1; 1 1];

x1 = A1\b1

b2=[7; 4; 6];

A2=[10 -1 0;-3 2 6; 5 1 5];

x2=A2\b2

b3=[-2; 16; -15; -15];

A3=[1 4 -1 1;2 7 1 -2; 1 4 -1 2; 3 -10 -2 5];

x3=A3\b3

x1 =

2

1

x2 =

-2.4000

-31.0000

9.8000

x3 =

5.0154

-1.2769

-11.0923

-13.0000

``

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