Question

3/a=9/b-10c solve for a.

Answer 1

For this case we have the following equation:
 3 / a = 9 / b-10c
 Rewriting we have:
 3 = a * (9 / b-10c)
 Clearing to have:
 a = 3 / (9 / b-10c)
 Answer:
 The value of a in terms of variables b and c is given by:
 a = 3 / (9 / b-10c)