Respuestas

2012-03-04T19:35:53+01:00

(x + 3) + 2( x - 9) = 9

x + 3 + 2x - 18 = 9

x + 2x = 9 + 18 - 3

3x = 24 | :3

x = \frac{24}{3}

x = 8

2012-03-04T22:07:16+01:00