F(-3)=121=112-k(-3)
121=112+3k
minus 112 both sides
9=3k
divide by 3
k=3
I don’t know there’s no picture B?
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.

Answer:
-7
Step-by-step explanation:
1. Combine Like Terms
3n-7=4n
2. Subtract 3n on both sides.
-7=n
3. You got your answer:)