Respuesta :
Answer:
i think e because we do not know the y or z values
Step-by-step explanation:
Answer:
C
Step-by-step explanation:
x +y -z= 8 -----(1)
x -y +z= 12 -----(2)
Adding equations 1 and 2 together,
x +y -z +x -y +z= 8 +12
Grouping like terms together,
x +x +y -y -z +z =20
2x= 20 (simplify)
x= 20 ÷2 (÷2 on both sides)
x= 10