Percent change problem

[1a2s3d4f5g6h7j8k9l]

If the width of a rectangle is decreased by 10% and the length is increased by 10%, find the percent change in the area of the rectangle.


Can someone please help? Thanks!

 

[1a2s3d4f5g6h7j8k9l]

Sorry Denis, but all I wanted was help getting started on these problems (like hints). I was not expecting them being fully done (but thank you Soroban).