Shiloh is 7 years older than courtney. shiloh's age is 13 years less than two times courtney's age. the system below models the relationship between shiloh's age (s) and courtney's age (c):

s = c + 7
s = 2c − 13

which of the following methods is correct to find shiloh's and courtney's age?

solve s + 7 = 2s − 13 to find the value of s.
solve c + 7 = 2c − 13 to find the value of c.
write the points where the graphs of the equations intersect the x-axis.
write the points where the graphs of the equations intersect the y-axis.