Question

3. Calculaţi:
a) 7x - 2-[-x - (-6x + 2)];
b) x + 5 – [3x - 6 - (2x – 10)];
C) x – 2 - {x – 3 – [5x – 4 - (6x – 2)]}; d) 9- {2x – [x – (1 – x) + (2x - 1)]}.
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Answer 1

Răspuns:

Explicație pas cu pas:

a) 7x - 2-[-x - (-6x + 2)]

7x - 2 - (-x + 6x - 2) = 7x - 2 - (5x - 2) = 7x - 2 - 5x + 2 = 2x

b) x + 5 – [3x - 6 - (2x – 10)]

x + 5 - (3x - 6 - 2x + 10) = x + 5 - (x + 4) = x + 5 - x - 4 = 1

C) x – 2 - {x – 3 – [5x – 4 - (6x – 2)]}

x - 2 - [x - 3 - (5x - 4 - 6x + 2)] = x - 2 -  [x - 3 - (-x - 2)] = x - 2 - (x - 3 + x + 2)

= x - 2 - (2x - 1) = x - 2 - 2x + 1 = -x - 1

d) 9- {2x – [x – (1 – x) + (2x - 1)]}

9 - [2x - (x - 1 + x + 2x - 1)] = 9 - [2x - (4x - 2)] = 9 - (2x - 4x + 2)

= 9 - (-2x + 2) = 9 + 2x - 2 = 7 + 2x