0.39,0.4. I got these answers because 0.39 has an extra digit the 0.3 so 0.3 becomes 0.30 and 0.39 is bigger than it. 0.4 is greater than 0.3 because the 4 in 0.4 is greater than 0.3. Hope This Helped :D
A) He wanted to create zero pairs on the left side of the equation to get a positive coefficient of x on the right side