What equation is equivalent to 2r^2-28r+38

Asoftball team played ten games, scoring 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 runs. they lost by one run in exactly five games. in each of their other games, they scored twice as many runs as their opponent. how many total runs did their opponents score?

Find the radius of a circle that has a circumference of 16. the formula for the circumference of a circle is c = 2tr, where r is the radius and c is the circumference. the equation solved for r is r = c over 2π. r=4 r= 8 r=12 r= 16

Me because i don't understand how to do it.: )