Answer: 1) 25b 2) ac 3)ba
1) Since b is unknown, your answer will be 25b
2) Since both variables, a and c, are unknown, your answer will be ac
3) Since both are unknown here, it will be ba!
Answer: 
Step-by-step explanation:
See attached image, it's direct formula substitution.
She missed 3 questions,
11/100 equals x/26
^set up this proportion
you get 286 equals 100x
and x equals 2.86
round this to 3 questions
to check your work, do 23/26