mohon bantuannya dengan cara terimakasih

cot B = 1/2 = sa/de => mi = √(1^2 + 2^2) = √(1 + 4) = √5
Sin B = de/mi = 2/√5
Cos B = sa/mi = 1/√5
(2 sin B - 8 cos B)/(5 sin B + 4 cos B)
= (2 . 2/√5 - 8 . 1/√5) / (5 . 2/√5 + 4 . 1/√5)
= (4/√5 - 8/√5) / (10/√5 + 4/√5)
= (-4/√5) / (14/√5)
= -4/14
= -2/7

cot B = cosB / sinB = 1/2
cosB = 1
sinB = 2

(2 sinB - 8 cosB)/(5 sinB + 4 cosB)
= (2.2 - 8.1)/(5.2 + 4.1)
= (4 - 8)/(10 + 4)
= -4/14
= -2/7

#CMIIW