Answer:
9. n=-15 , 10. f=6, sorry i can't help you more I am just tired and have to get some rest but i hope this helps
Explanation:
9. Eight less than 1/3 a number n is -13
so -13 = 1/3n -8
then
-5 = 1/3n
multiply 3 to each side
-15 = n
10. a number f multiplied by -12.3 is -73.8
so -12.3f= -73.8
divide -12.3 on each side
so f=6