Hi there! :)
Answer:
b=8
*The answer must have a positive sign.*
Explanation:
Lesson: Division property of equality
Distributive property: a(b+c)=ab+ac
First, you divide by 7 from both sides of an equation.

Then, you simplify and solve. Divide by the numbers from left too right.

Final answer is b=8.
I hope this helps you!
Have a nice day! :)
-Charlie
:D