The first problem, factor out the n. The second problem, first multiply both sides by x. Does this help?
I see a number of mistakes here.
n/a = cd/a - n
This isn't right either, for the same reason. If you want to multiply both sides by a, you have to multiply ALL terms by a, like this:n + n/a = cd
n+ n = cda
na + n = cda
Here's what you should do: one way of factoring is to take out the greatest common monomial factor -- in a sense, you are reversing the distributive property. Since on the left side there is a common factor of n, you "take it out":
You can see that this is true by going backwards and distributing the n. Now that you have n times something, you can divide both sides by that other factor:
LaTeX is the use of math tabs. You put the square brackets around 'math' like this [tex] and you close by inserting a similar tab but with '/' in front of 'math'. This allow the ease of display of some functions and fractions
If it's B, then
Multiply throughout by bc. Some b and c will cancel out, giving;
Remove nc from both sides, and remove 2 b too from both sides;
Divide by (b-c);
Looks like you did well!