teman plis jawab soal ini ya pakai jalan, plis banget soalnya gurunya galak

5phi/6 = 150
Sin150 = 1/2

sinA.cosB = 1/2[sin(A+B) + sin(A-B)]
2/5 = 1/2 [sin150 + sin(A-B)]
2/5 = 1/2 [1/2 + sin(A-B)]
2/5 ÷ 1/2 = 1/2 + sin (A-B)
1/5 = 1/2 + sin(A-B)
sin(A-B) = 1/5 - 1/2 = -3/10

Jadi jawabannya -3/10

I did my best