Question

Daca x/y=2/3 atunci 2x+y/x+2y este ?

Answer 1

Răspuns:

Explicație pas cu pas:

x/y = 2/3  ⇒  x = 2  si y = 3

( 2 x + y ) / ( x + 2 y ) =

= ( 2 × 2 + 3 ) / ( 2 + 2 × 3 ) =

= 7/ 8

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Sau:

x/y = 2/3 ⇒ x/2 = y/3 = k ⇒   x = 2 k  si y = 3 k

( 2 x + y) / ( x + 2 y ) =

= ( 2 × 2 k + 3 k ) / ( 2 k + 2 × 3 k ) =

= 7 k / 8 k =

= 7/8

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Sau:  x/y = 2/3 =>   y = 3 x/2

( 2 x + y ) / ( x + 2 y ) =

= ( 2 x + 3 x/2 ) / ( x + 2 · 3 x/2 ) =

= ( 4 x + 3 x ) / 2 : ( x + 3 x ) =

= 7 x/2  × ( 1/4 x) =

= 7 x/ 8 x =

= 7/8