Respuesta :

To distribute the 2. 

2(z-12)-1=z-25+z

First distribute the 2. 
2z-24-1=z-25+z

Combine like terms on both sides.
2z-25=2z-25

The two equations have ended up the same. They have an infinite number of solutions. 
2z-24-1=z-24-z
2z-25=24
2z=49
z=49/2