For this case we must find the value of the variable "x" of the following equation:
![12 = x + 3](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ol905sugw5dyoxisdrn6pqf3am0qtcvoqu.png)
So, we follow the steps:
Subtracting 3 from both sides of the equation we have:
![12-3=x+3-3](https://img.qammunity.org/2020/formulas/mathematics/middle-school/z5z2xazunvb4mmv9jn0nh0q8i1xpeqbn7h.png)
Different signs are subtracted and the sign of the major is placed:
![9 = x\\x = 9](https://img.qammunity.org/2020/formulas/mathematics/middle-school/z6pbdidbmuo8957yztag1pwrtccgptrkjf.png)
Thus, the value of x is 9.
Answer:
![x = 9](https://img.qammunity.org/2020/formulas/mathematics/high-school/bd39pfqtl19oh38prsz5mttgxgd7xiyxll.png)