Question

Help with matrices

Answer 1

the inverse of a 2x2 has a pretty simple formulation: swap topleft with bottom right, and negate the other two, then divide it all by the determinant

a b invertes to d/detA -b/detA
c d -c/detA a/detA

but if you want to get real fancy, just augment the 2 matrixes

[A|b1 b2 b3 b4 ...] -> [ I | x1 x2 x3 x4 ...]