Answer:

Step-by-step explanation:
x² = 19x + 12
⇔ x² - 19x - 12 = 0
Calculating the discriminant :
b² - 4ac = (-19)² - 4×1×(-12) = 409
The discriminant is positive ,then the equation has two solutions.

Yes it is possible because the acute angle is less then 90 degrees meaning its inside the angle
It means <span>9 is not an element of T. hope it helped</span>