Let x=
⎛ a c e ⎞
⎝ b d f ⎠
then multiplying we get:
⎛ a c e ⎞
⎝ -6a+2b -6c+2d -6e+2f ⎠=
⎛ 10 6 8 ⎞
⎝ 4 12 2 ⎠
Therefore: a=10, c=6, e=8 and:
-6a+2b=4, -60+2b=4, 2b=64, b=32;
-6c+2d=12, -36+2d=12, 2d=48, d=24;
-6e+2f=2, -48+2f=2, 2f=50, f=25.
Hence x=
⎛ 10 6 8 ⎞
⎝ 32 24 25 ⎠