Tolong dibantu nomer 23. Makasih

Matriks
AB = C --> B = A⁻¹ . C

23] | p....q|..|x|..= |p|
.......|q.....p|..|y|.....|q|

|px + qy|...= |p|
|qx + py|......|q|

px + qy = p
qx + py = q
Secara langsung misal y = 0
px + q(0) = p
px = p
x = p/p
x = 1

qx + py = q
q(1) + p(0) = q
q + 0 = q
q = q

nilai x = 1 dan y = 0
maka x + y = 1 + 0 = 1
Jadi x + y adalah 1