I need help understanding this we are doing increse/ decrese

Apositive number a or the same number a increased by 50% and then decreased by 50% of the result?

Select the correct answer from each drop-down menu. the table shows the annual sales revenue for different types of automobiles from three automobile manufacturers. sales revenue (millions of dollars) suv sedan truck marginal total b & b motors 22 15 9 46 pluto cars 25 27 10 62 panther motors 26 34 12 72 marginal total 73 76 31 180 the company with the highest percentage of sales revenue from sedans is . of the annual sales revenue from suvs, the relative frequency of pluto cars is .

Whats are the trickiest steps to do when adding or subtracting rational expressions? how does knowledge of rational numbers u in adding and subtracting rational expressions?