It looks like you might have intended to say the roots are 7 + i and 5 - i, judging by the extra space between 7 and i.
The simplest polynomial with these characteristics would be

but seeing as each of the options appears to be a quartic polynomial, I suspect f(x) is also supposed to have only real coefficients. In that case, we need to pair up any complex root with its conjugate to "complete" f(x). We end up with

which appears to most closely resemble the third option. Upon expanding, we see f(x) does indeed have real coefficients:

Answer:
The recoil velocity of the gun is
and is pointing in opposite direction to the velocity of the bullet.
Step-by-step explanation:
Use conservation of linear momentum, which states that the momentum of the bullet (product of the bullet's mass times its speed) should equal in absolute value the momentum of the recoiling gun (its mass times its recoil velocity).
We also write the mass of the bullet in the same units as the mass of the gun (for example kilograms). Mass of the bullet = 0.010 kg
In mathematical terms, we have:

Answer:
0.8*x*(‑5)/7
Step-by-step explanation:on the qraph
Y = -5x + 12 since the slope of that line is -5x and in order to pass through that point the y intercept must be 12