Step-by-step explanation:
6x - 3x^2 + 2x^2 -2x = 5x^2 + 15x
4x -x^2 = 5x^2 + 15x
-11x - 6x^2 = 0
-6x^2 - 11x = 0
use the quadratic formula
(-b±√(b²-4ac))/(2a)
ABF= 28 degrees
BCD= 28 degrees since vertical angle are congruent
ABC= 180 -28 = 152 degrees
Answer:
5
Step-by-step explanation:
