B completes the line bc it goes 1 2 3 4 then 5
To solve for x in terms of b, simply treat b as a number, and solve for x as usual: first of all, we expand the left hand side:

Subtract 10 from both sides:

Divide both sides by -2b:

This means that in particular, if we set
, we have

To factor polynomials, find a common number to remove and leave the rest in parentheses. I did the odds, now you try the evens. If you still need help,, let me know.
1. 3 (x+4)
3. 5 (x+6y)
5. 3(2 a^2 + 9)
7. 3d (7c -1)
9. 15a (ab - 2b)
Number set:
18, 36, 900
GCF:
9
The final stock price is $48.54