Jawabanmu

2014-05-27T23:28:12+07:00
A) L = π  r²
=3,14 . 4900
=15 386 m²

b) (C-A)x = 50 000
(7-2) x = 50000
x = 10000

Maka
A = 2 . 10000 =20 000
B = 5 . 10000 = 50 000
C = 7 . 10000 = 70 000
Jumlah = 140 000

:)