Could You Help me answer these algebra questions?

you must first get the common denominator

basic "butterfly" rule is to add (C+6 times 20) and (C-5 times 8)

so you get 20C + 120 +8C - 40

all of this is over the common denominator (8 times 20)

so it is now at 28C + 80 over 160....... AKA (28C+80)/160

now you simplify top and bottom by dividing by 4 so now you get (7C+20)/(40)

for #2 you do the same

Add (2 times S+3) with (2 times S-3)

now you've got (2S+6) + (2S -6)

which equals 4S

all of which is over the common denominator (s-3) times (s+3) = S^2 -9

answer is 4S/(S^2 - 9)

1. c+6/8 + c-5/20 = c+3/4 + c-1/4 (simplifying each fraction by dividing numerator and denominator by 2 for the first one, and 5 for the second) = 2c+2/4 (you can combine the fractions once they have a common denominator) = 2c + 1/2 (simplifying 2/4 by dividing numerator and denominator by 2).

2. 2/(s-3) + 2/(s+3) (assume that's what you mean by "2 over s-3" and "2 over s+3") =

2(s+3)/((s+3)(s-3)) + 2(s-3)/((s-3)(s+3)) (multiplying numerator and denominator by the same term) =

(2(s+3)+2(s-3))/(s+3)(s-3) (again, we have the same denominator) =

(2s+6+2s-6)/(s+3)(s-3) = 4s/(s^2-3s+3s-9) = 4s/(s^2-9) (where "s^2" means "s squared")

Do they equal anything or are they expressions?