Problem $2\mathrm{.}25$ from the text. Assume that part A must pass through machines $1$ and $2$ to be completed. For example, machine $1$ drills a hole and machine $2$ puts a taper in the hole made at machine $1.$ Similarly, part B must pass through both machines $3$ and $4$ to be completed. Then parts A and B are combined to make a part C at station $5.$ Please note that on problem $2\mathrm{.}25$ that "the desired output $06"$ means the output of station$6$ and that "input $11$ to machine $1"$ is a typo and means the input to machine $1($it ought to read "input to machine $1").(24$ pts$)$

Determine an equation for the required input for both machines $1$ and $3($not just machine $1$ as stated in the problem.$)$