Assuming the function is x^2
Answer:

Step-by-step explanation:

It would help the chain run smoother and work better and faster.
Answer:
x = -7 and x = 3
Step-by-step explanation:
x² + 4x - 21 = 0 factors as follows: (x + 7)(x - 3) = 0.
Then x = -7 and x = 3.