The equation $\frac{c}{a} = r - d$ expresses a relationship between four variables: $c$, $a$, $r$, and $d$. To solve for one variable in terms of the others, you can rearrange the equation accordingly.

Solving for $c$:

Multiply both sides by $a$ to isolate $c$: $c = a(r - d)$

Solving for $a$:

Divide both sides by $(r - d)$ to isolate $a$: $a = \frac{c}{r - d}$

Solving for $r$:

First, add $d$ to both sides: $\frac{c}{a} + d = r$

So, $r = \frac{c}{a} + d$

Solving for $d$:

Subtract $r$ from both sides and then multiply by $-1$: $d = r - \frac{c}{a}$

Would you like to go over a specific variable or an example?

Here are 5 related questions:

1. What happens to $c$ when $r$ and $d$ are equal?
2. How does changing $a$ affect the value of $r$?
3. Can $d$ be negative in this equation?
4. If $r = 0$, what does that imply about the relationship between $c$, $a$, and $d$?
5. How would you solve this equation if $r$ and $d$ are functions of time?

Tip: When solving equations involving fractions, it's often useful to eliminate the fraction by multiplying both sides by the denominator, as it simplifies the equation significantly.