tolong dijawab caranya ya:)

Bp :Bm =5:7
Bb: Bm=3:2
Bb-Bm =4.200
Bm+Bp=....???
Bm = 2/3-2 ×4.200
=2/1 × 4.200
=8400
Bp. =5/7 × 8.400
= 5 × 1200
=6000
Bm+Bp= 8400+6000=14400