Not sure about the first one,
The second one is 1/9.
Step-by-step explanation:

Answer:
f(-8) = 169
Step-by-step explanation:
Answer:
like terms: (3n,-n),(7,-3)
Step-by-step explanation:
Answer:
2(s-c)/ a^2 = v
Step-by-step explanation:
s = 1/2 a^2 v+c
Subtract c from each side
s -c = 1/2 a^2 v+c-c
s-c = 1/2 a^2 v
Multiply each side by 2
2(s-c) = 2* 1/2 a^2 v
2(s-c) = a^2 v
Divide each side by a^2
2(s-c)/ a^2 = a^2 v /a^2
2(s-c)/ a^2 = v