Respostas

2014-04-01T18:06:01-03:00
X-4x+15x=245-5
12x=240
x=240/12
x=20
2014-04-01T18:08:02-03:00
x+(5-4x)=5(49-3x)
x+5-4x=245-15x
x+15x-4x=245-5
12x=240
x=240/12
x=20