Tolong bantu jawab ya..

A) Det= ad-bc =20-(-48) = 20+48 = 68
b) Det=ad-bc =28x-(-6x) = 28x+6x = 34

A. D=(5.4) – (-6.8)
= 20 – (-48)
= 20 + 48
= 68

b. D= (4x.7) -(-2x.3)
= 28x + 6x
= 34x