To solve, you would need to make two equations and substitute one in for the other. Let a = # of adults, and c = # of children
5a + 2c = 1,220
a + c = 295
a + c = 295
-c -c
a = 295 - c
5(295 - c) + 2c = 1,220
1,475 - 5c + 2c = 1,220
1,475 - 3c = 1,220
1,475 - 3c = 1,220
-1,475 -1,475
-3c = -255
-3c/-3 = -255/-3
c = 85
a + c = 295
a + 85 = 295
-85 -85
a = 210
210 adults attended the dance recital
Hope this helps!
If angle ec is a bisector then angles Bec and ced are the same making them both 4x+1. we know a line segment equals 180°. so if we take the 11x-12 and add it to 2(4x+1) we end up with 19x-10=180. you add 10 to both sides and get 19x=190 then you divide by both sides. you'll end up with x=10. you plug In the 10 with aeb and aec and add them together to get 139°. if you're looking for the equation, it's 15x-11.
That 1 is greater than 1 because 1 is positive and -3 is negative