Answer to get mark as ! answer this math problem and explain step by step!

*numbers spelled out because zero key is broken sorry*

To get ten percent of forty you divide forty by ten which is 4. Then to subtract the discount, subtract 4 from forty and end up with 36. So the answer is $36. 
Hope this helps!

I'm pretty sure it's b). i try drawing the functions out and b is the one that stands out or isnt a "line"

Just tell koda to adjust the number of shapes himself.