Can someone please help me?

Which property was used to simplify the expression? 3c+9 +4c=3c+4c+9

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 .

Problem number 26 of the rhind papyrus says: find a quantity such that when it is added to of itself the result is a 15. the modern day equation that models this problem is x + x = 15. what is the solution to the equation? x = 10 x = 12 x = 15 x = 30