Răspuns:
Explicație pas cu pas:
a = 2; b = 5
( 3 a + 2 b ) / ( a + b ) = ( 3 × 2 + 2 × 5 ) / ( 2 + 5 ) = 16 / 7
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sau:
a / b = 2 / 5 ⇒ 2 b = 5 a ⇒ b = 5 a / 2
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( 3 a + 2 b ) / ( a + b ) = 16 / 7
= ( 3 a + 2 × 5 a / 2 ) / ( a + 5 a / 2 ) =
= ( 3 a + 5 a ) / ( 2 a + 5 a ) / 2 =
= 8 a : ( 7 a / 2 ) =
= 8 a × ( 2 / 7 a ) =
= 16 / 7 =
= 2 intregi si 2 / 7
