A shirt was marked up by 80% and then sold at a 35% discount. If the sale price was R94.70, what was the original cost price?

Let $C$ be the original cost price.
The shirt was marked up by 80%, so the marked price $M$ is:

The sale gives a discount of 35% from the marked price, so the sale price $S$ is:

The shirt is sold for R94.70, so $S = \text{R}94.70$.

We know