mldivide

auto a = [
     1, -1,  1,
     2,  2, -4,
    -1,  5,  0].sliced(3, 3);
auto b = [
     2.0,  0,
    -6  , -6,
     9  ,  1].sliced(3, 2);
auto t = [
     1.0, -1,
     2  ,  0,
     3  ,  1].sliced(3, 2);

auto x = mldivide(a, b);
assert(x == t);

auto a = [
     1, -1,  1,
     2,  2, -4,
    -1,  5,  0].sliced(3, 3);
auto b = [
     2.0,
    -6  ,
     9  ].sliced(3);
auto t = [
     1.0,
     2  ,
     3  ].sliced(3);

auto x = mldivide(a, b);
assert(x == t);

auto a = [
    -0.57,  -1.28,  -0.39,   0.25,
    -1.93,   1.08,  -0.31,  -2.14,
     2.30,   0.24,   0.40,  -0.35,
    -1.93,   0.64,  -0.66,   0.08,
     0.15,   0.30,   0.15,  -2.13,
    -0.02,   1.03,  -1.43,   0.50,
    ].sliced(6, 4);

auto b = [
 -2.67,
 -0.55,
  3.34,
 -0.77,
  0.48,
  4.10,
].sliced;

auto x = [
    1.5339,
    1.8707,
   -1.5241,
    0.0392].sliced;

import std.math: approxEqual;
assert(a.mldivide(b).approxEqual(x));