Exercise 20 Page 85

To solve the equation we need to isolate b on one side of the equation. By adding 19 to both sides, we can cancel it from the right-hand side.

We find b=42 is the solution to the equation. To check that we have the correct solution, we can substitute b=42 into the original equation and simplify.

Since the left-hand side and right-hand side are equal, b=42 is a correct solution.