Answer: 14.825
Step-by-step explanation:
First , do 2 * 5.3 because it's 2a, you'll have to do 2 * a. This equals 10.6.
Second, you'll need to do 5.3 * 1.25. Why? Because in the problem you need to do a * b, which is that. It equals 6.62500.
Lastly, put it all together! 10.6 + 6.62500 - 2.4 equals 14.825.