Question

2. Rezolvati in multimea numerelor intregi ecuatile:
a) 5x-2x(x-7)-9=x+15
b) 3(2x+7)-14=2(2x-5)+3
c)2[3(2x-3)-8]-9=5
d) 3(3x+4)-5=2(2x+7)+13
DAU COROANA PLUS 20 DE PUNCTE! AM NEVOIE URGENTTT!

Answer 1

Răspuns:

Explicație pas cu pas:

a) 5x-2(x-7)-9=x+15

5x - 2 x + 14 - 9 = x + 15

3x + 5 = x + 15

3x - x = 15 - 5

2x = 10

x = 10 : 2

x = 5

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b) 3(2x+7)-14=2(2x-5)+3

6x + 21 - 14 = 4x - 10 + 3

6x + 7 = 4x - 7

6x - 4x = - 7 - 7

2x = - 14

x = (-14) : 2

x = - 7

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c)2[3(2x-3)-8]-9=5

2 × ( 6x - 9 - 8 ) - 9 = 5

2 × ( 6x - 17 ) - 9 = 5

12x - 34 - 9 = 5

12x - 43 = 5

12x = 5 + 43

x = 48 : 12

x = 4

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d) 3(3x+4)-5=2(2x+7)+13

9x + 12 - 5 = 4x + 14 + 13

9x + 7 = 4x + 27

9x - 4x = 27 - 7

5x = 20

x = 20 : 5

x = 4 ∈ Z