Let's call the markup as x. The markup is the difference in cost between your selling price and the amount you spent to make your product. Bismark Tractor put a markup of 26% on cost, which means that the selling price was 26% more than the cost price. Since he paid $450 for the part, this gives to us the following equation
![450+x=(1+0.26)\cdot450](https://img.qammunity.org/2023/formulas/mathematics/college/w7bu146ecict4h45sj68kk24tqq7f9jpq3.png)
Solving it for x, we have
![\begin{gathered} 450+x=(1+0.26)\cdot450 \\ 450+x=1.26\cdot450 \\ x=1.26\cdot450-450 \\ x=0.26\cdot450 \\ x=117 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/c33m36zzydck0zduf03opi7tqqjprl1km5.png)
The markup was $117.