Cho A khả nghịch, tìm X từ AX − 2B = C

X=A−1(C+2B)X = A^{-1}(C + 2B)X=A−1(C+2B)

X=(C+2B)A−1X = (C + 2B)A^{-1}X=(C+2B)A−1

X=A(C+2B)X = A(C + 2B)X=A(C+2B)

X=A−1(C−2B)X = A^{-1}(C - 2B)X=A−1(C−2B)