The 15 lbs at $7=$105
So multiple 5x9 as a test and check results. 105-45=60
Here you can see that 60 is a factor of 6 by 10 so you got lucky and got the answer of 10lbs at $6 & 5lbs at $9=15 lbs at $7 average
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:
8.45 is the answer
Step-by-step explanation:
Hope it helps you
Answer: the answer has to be a because the other ones are not even close
Step-by-step explanation:
Answer:
20% error
Step-by-step explanation:
easy
9.4/7.8 or do 0.078x=9.4
1.20512820513
round to nearest tenth
1.2
means
20% error