Question 1120748
the total mass of A, B C D was 280kg.
a + b + c + d = 280
 If the mass of A decreased by 30kg, the mass of B was increased by 10kg,
 the mass of C was halved and the mass of D was tripled, the 4 masses would be equal
a - 30 = 3d
a = (3d+30)
:
b + 10 = 3d
b = (3d-10)
:
.5c = 3d
c = 6d
Replace a, b, c in the first equation
(3d+30) + (3d-10) + 6d + d = 280
combine like terms
13d + 20 = 280
13d = 280 - 20
13d = 260
d = 260/13
d = 20 kg
then
a = 3(20) + 30
a = 90 kg
and
b = 3(20) - 10
b = 50 kg
and
c = 6(20)
c = 120 kg
:
Check: 90 + 50 + 120 + 20 = 280
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