ada yg tau kaka tolong di jawab ya

EF = (AD x BE + BC x AE) / AB
12 = (9 . 4 + 14 . x) / (4 + x)
12 = (36 + 14x) / (4 + x)
12(4 + x) = 36 + 14x
48 + 12x = 36 + 14x
14x - 12x = 48 - 36
2x = 12
x = 12 / 2
x = 6 cm

Jawaban A