standard_description: Given a rectangle, parallelogram, trapezoid, or regular polygon, describe the rotations and reflections that carry it onto itself.
problem_activity: Solve. Show or explain your work.
a.
$$\begin{align} 7,396 \\ {–\ 2,145}& \\ \hline \end{align}$$
b.
$$87,625-5,031=$$
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c.
$$\begin{array}{r} &19,850\\ -\!\!\!\!\!\!&15,761\\ \hline \end{array}$$


aligns: no