31. I'm not positive but give it a shot if it is wrong message me back!
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<u>Answer:</u></h3>

<h3>
<u>Step-by-step explanation:</u></h3>
Here , two circles are given which are concentric. The radius of larger circle is 10cm and that of smaller circle is 4cm . And we need to find thelarea of shaded region.
From the figure it's clear that the area of shaded region will be the difference of areas of two circles.
Let the,
- Radius of smaller circle be r .
- Radius of smaller circle be r .
- Area of shaded region be
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<u>Hence </u><u>the</u><u> </u><u>area</u><u> </u><u>of</u><u> the</u><u> </u><u>shaded </u><u>region</u><u> is</u><u> </u><u>2</u><u>6</u><u>4</u><u> </u><u>cm²</u><u>.</u></h3>
Xy(9x)(5x^3y) so the greatest common factor is xy