Respuesta :

loneguy

[tex]3|x-7| = 15\\\\\implies |x-7| =\dfrac{15}3\\\\\implies |x -7| = 5\\\\\implies x -7 = 5 ~~ \text{or}~ x - 7 = -5\\\\\implies x = 12 ~~\text{or}~~ x = 2[/tex]

successvrzo2
Ez way to do it use distribution 3x-21=15 add 21 to 15 =36
3x=36 divided by 3 both side x=12 x=2