I believe a would be on the first line.
21 and 22 because 21+22=43
180=90+50+x
180=140+x
x=180-140=40
X=40
Let x represent the amount of lawn mowers that were manufactured
The company has to pay $34,816 before they even make any lawn mowers plus $388 per lawn mower.
((34816+388x)/x)=660
34816+388x=660x
34816=272x
X=128
Therefore, there were 128 lawn mowers manufactured