Question

determinati numerele abc stind ca a si b sunt direct propprtionale cu 5 si 8 b si c sunt invers proportionale cu 3 si 2 iar 3a +2b-c=57

urgent coroana va rog

Answer 1

a/b = 5/8 => a = 5b/8

b/1/3 = c/1/2 => 3b = 2c => c = 3b/2

inlocuim in functie de b :

3a + 2b - c = 57

15b/8 + 2b - 3b/2 = 57 |×8

15b + 16b - 12b = 456

19b = 456

b = 456 : 19

b = 24

a = 5×24/8 = 5 × 3 = 15

c = 3×24/2 = 3 × 12 = 36


a = 15
b = 24
c = 36
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