Hi there! :)
Answer:
b=19
*The answer must have a positive sign.*
Explanation:
Lesson: Addition/Subtraction/Multiplication/ and Division property of equality
First, you add by 7 from both sides of an equation.
![b-7+7=12+7](https://img.qammunity.org/2019/formulas/mathematics/college/skm6yaposjy36z4y1ccg9xhmwnkzibkbs5.png)
Then, you add by the numbers from left to right.
![12+7=19](https://img.qammunity.org/2019/formulas/mathematics/college/g7ux3pde71dqvsusa4jtlxy24dpyxrn6if.png)
Final answer is b=19
I hope this helps you!
Have a nice day! :)
:D
-Charlie
Thank you so much! :)