Question

Rezolvati urmatoarele ecuatii:

a) 5(3x-2)+3x-6(8x-13)=16(9-2x)-78

b) 2(3x+4)-5(2x-3)-2=7(2x-4)+2(8-5x)+3x

c) 2(3x-4)+5(6x-7)-3x=9(x+10)+11(x+12)+8

Answer 1

Răspuns:

a)

5 (3x - 2) + 3x - 6 (8x - 13) = 16 (9 - 2x) - 78

15x - 10 + 3x - 48x + 78 = 144 - 32x - 78

- 30x + 68 = 66 - 32x

- 30x + 32x = 66 - 68

2x = -2

x = -1

b)

2 (3x + 4) - 5 (2x - 3) - 2 = 7 (2x - 4) + 2 (8 - 5x) + 3x

6x + 8 - 10x + 15 - 2 = 14x - 28 + 16 - 10x + 3x

- 4x +21 = 7x - 12

- 4x - 7x = - 12 - 21

- 11x = - 33

x = - 33 : (- 11)

x = 3

c)

2 (3x - 4) + 5 (6x - 7) - 3x = 9 (x + 10) + 11 (x + 12) + 8

6x -8 + 30x - 35 - 3x = 9x + 90 + 11x + 132 + 8

33x - 43 = 20x + 230

33x - 20x = 230 + 43

13x = 273

x = 273 : 13

x = 21