Respuesta:
7z-[(2z+y)-(-5y+3z)+9]-12z eliminar los signos de agrupación
7z-\left[\left(2z+y\right)-\left(-5y+3z\right)+9\right]-12z 7z -[2z+y+5y-3z+9]-12z 7z -2z-y -5y+3z-9-12z 7z -2z+3z-12z -y-5y-9 -4z -6y -97z−[(2z+y)−(−5y+3z)+9]−12z7z−[2z+y+5y−3z+9]−12z7z−2z−y−5y+3z−9−12z7z−2z+3z−12z−y−5y−9−4z−6y−9
