a:b =7:9 jika jumlah a+b=80 berapa kg selisih berat mereka

a/b = 7/9
a = 7/9 b

a + b = 80
7/9b + b = 80
16/9b = 80
b = 80 x 9/16
b = 45

a = 7/9 b
a = 7/9 x 45
a = 35

Selisih berat = 45 - 35 = 10 kg

Selisih a-b=minus 10.selisih b-a=10.
a=35
b=45