Respuesta :
Answer:
x = 9
Step-by-step explanation:
3 + x = 12
Subtract 3 from both sides.
x = 9
Since the word “ sum” signifies addition, the equation would be x+3=12
Answer:
x = 9
Step-by-step explanation:
3 + x = 12
Subtract 3 from both sides.
x = 9