Question

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Answer 1

Răspuns:

Explicație pas cu pas:

a)

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

r = 5x - 7 - (2x + 1) = 5x - 7 - 2x - 1 = 3x - 8

x + 2 = 3x - 8

3x - x = 2 + 8

2x = 10

x = 10 : 2 = 5

b)

r = x^2 - 3x + 2 - (x^2 - x + 1) = x^2 - 3x + 2 - x^2 + x - 1 = -2x + 1

r = x^2 + 2x - 11 - (x^2 - 3x + 2) = x^2 + 2x - 11 - x^2 + 3x - 2 = 5x - 13

-2x + 1 = 5x - 13

5x + 2x = 1 + 13

7x = 14

x = 14/7 = 2