Resposta :
5x - 3 + x = 2x + 9
5x + x - 2x = + 9 + 3
6x - 2x = 12
4x = 12
x = 12
4
x = 3
Confirmando:
5 * 3 - 3 + 3 = 15
2 * 3 + 9 = 15
5x + x - 2x = + 9 + 3
6x - 2x = 12
4x = 12
x = 12
4
x = 3
Confirmando:
5 * 3 - 3 + 3 = 15
2 * 3 + 9 = 15