Question

Determinati a,b,c care sunt invers proportionale cu 2 , 4 si 3 si verifica a+2b+c=80

Answer 1

a / ( 1 / 2 ) = b = ( 1 / 3 ) = c / ( 1 / 7 ) = k
a = k / 2
b = k / 3
c = k / 7

a - b - c = 1
k / 2 - k / 3 - k / 7 = 1
( 21 k - 14 k - 6 k ) 42 = 1
k = 42
a = 42 / 2=21
b = 42 / 3=14
c = 42 / 7=6