I have a question, what is 71.5 - 28.742

Which answer is it for it to be simplified completely?

Solving systems of linear equations: tables represent two linear functions in a systemöwhat is the solution to this system? 0 (10)0 (1.6)0 18,26)0 18-22)

An investment decreases in value by 30% in the first year and decreases by 40% in the second year. what is the percent decrease in percentage in the investment after two years