Question

ex: 6,7,8. va rog, dau coroana

Answer 1

1 ) x + 2a - 2b = 8

x + 2 ( a - b ) = 8

x + 8 = 8 => x = 0

x + 1  = 30 + 5a - 5b

x + 1 = 30 + 5 ( a - b )

x + 1 = 30 + 20

x + 1 = 50

x = 49

x + 16 + 8a - 8b  = 49

x + 16 + 8 ( a - b ) = 49

x + 16 + 32 = 49

x + 48 = 49

x = 1

2 ) 75 bani --> un caiet ;

75 × 3 = 225 bani --> un stilou ;

225 × 2 = 450 bani --> un pix ;

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75 + 450 + 225 = 75 + 675 = 750 bani = 7,50 lei ;

3 ) a + b = 27 => a = 27 - b

2a + 3b  = 71

2 × 27 - 2b + 3b = 71

b = 71 - 54 => b = 17

a = 27 - 17 => a = 10

3a - b = 30  - 17  = 13