The point StartRoot x EndRoot is plotted on the number line. A number line going from 9.8 to 10.7. StartRoot x EndRoot is plotted slightly to the left of 10.2. What whole number best approximates the value of x

Could somebody me with this radical simplification?

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

Delbert keeps track of total of the total number of points he earns on homework assignments, each of which is worth 60 points. at the end of the semester he has 810 points. write an equation for delbert’s average homework score a in terms of the number of assignments n.