Question

VA ROG ! ESTE URGENT! EXERCITIUL 19 ! DAU CORONITA .

Answer 1

A) x+5y+z=x+3y+2y+z=2*14=28

B)3x+15y+3z=3x+9x+6x+3z=6*14=84

C)5x+11y-2z=5x+15y-4y-2z=5*14-2*14=3*14=42

D)5x+19y+2z=5x+15y+4y+2z=7*14=98

Answer 2

x + 3 y = 2 y + z = 14

a)  x + 5 ·  y + z = ( x + 3 · y ) + ( 2 · y + z ) = 14 + 14 = 28

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b)  3 · x + 15 · y + 3 · z = 84

= 3 · ( x + 3 y  + 2 · y + z ) =

= 3 · ( 14 + 14 ) =

= 3 · 28 =

= 84

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c)   5 ·  x + 11 · y - 2 z =  42

= 5 · ( x + 3 · y ) -  2 ·  ( 2 y + z ) =

= 5 · 14 - 2 · 14 =

= 14 · ( 5 - 2 ) =

= 14 · 3 =

= 42

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d)   5 · x + 19 y + 2 z = 98

= 5 · ( x + 3 y ) + 2 · ( 2 y + z ) =

= 5 · 14 + 2 ·14 =

= 14 · ( 5 + 2 ) =

= 14 · 7 =

= 98