Answer:
The correct answer is <em>b = 36</em>
Step-by-step explanation:
In order to find out what b is, you must find out what 9/10 is.
9/10 is 0.9. This will later be used to check our answer.
Now, solve by using cross-multiplication
b * 10 = 9 * 40.
Then use the commutative property to reorder the terms
10b = 9 * 40
Now Multiply 9 * 40 = 360
10b = 360
Now divide both sides of the equation by 10
<em>b = 36</em>
