<human>:  A new edition Geometry book has 450 pages which are 230 pages less than twice as many pages as the old edition. How many pages did the old edition Geometry book have?
<bot>: Define a variable ** Let x be the number of pages of the old edition Geometry book
How many pages does the new edition Geometry book have? ** The new edition Geometry book has 2x - 230 = 450 pages
Write an equation ** 2x = 450 + 230
Add 230 to both sides ** 2x = 680
Divide by 2 ** x = <<340=340>>340 pages
#### 340