Respuesta :

reinhard10158

Step-by-step explanation:

a + b + c + d = 279

a = b

c = 2×(a + b) = 2×(2a) = 4a (because a = b)

d = 3×b = 3×a = 3a

so, the first equation looks like

a + a + 4a + 3a = 279

9a = 279

a = 31

b = 31

c = 4a = 4×31 = 124

d = 3a = 3×31 = 93