Hello!
∠GCE = 14° (corresponding angles)
∠GEC = 180° - 78° - 14° (sum of angles in a triangle)
∠GEC = 88°
4x + 88° = 180°
4x = 180° - 88°
4x = 92°
x = 23°
Answer:
B
Step-by-step explanation:
Given
x(3x + 5) - 4(3x + 5) ← factor out (3x + 5) from each term
= (3x + 5)(x - 4) → B


and surely you can take it from there,
recall, that, since we changed the bounds, with the u(x),
you don't need to change the variable "u", and simply,
get the integral of it, simple enough, and apply those bounds