Question

the dimension of a rectangle are such that its length is 5 in. more than its width.if the length were doubled and if the width were decreased by 2 in. the are would be increased by 70n in^2

Answer 1

Sorry I'm trying to read you question, but there are quite a bit of typos.

Facts:
1.) Area = Length * Width
2.) Length = 5in. + Width
So, we know: Area = (5in + Width) * (Width)

Now if we double the Length and decrease the Width by 2in., the equation would change to:
1.) Length = 2[5in+(Width-2in)]

Your new area would be: Area = 2[5in+(Width-2in)] * (Width-2in)

To find the change in area, you need to subtract the first equation from the second:

{2[5in+(Width-2in)]*(Width-2in)} - {(5in + Width) * (Width)}

I hope that helps. If not, just rewrite your question so it's easier to read please.