solve by the matrix method

x1+2x2-x3+x4=28

2x1+4x2-3x3+x4=55

-4x1+8x2-12x3-x4=-93

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

[Torsten]

What do you call "the matrix method" ?

Answer 1

[Dyuman Joshi]

Use mldivide, \

Answer 2

[Star Strider]

Solving it symbolically —

syms x1 x2 x3 x4 

Eqns = [x1+2*x2-x3+x4==28
        2*x1+4*x2-3*x3+x4==55
        -4*x1+8*x2-12*x3-x4==-93
        -x1+16*x2+x3+2*x4==-7]

Eqns = 

[A,b] = equationsToMatrix(Eqns)

A = 

b = 

x1x2x3x4 = linsolve(A,b)

x1x2x3x4 = 

.