If the perimeter is 98 cm, the sum of the lengths of two adjacent sides is 49 cm.
... (2x -1) + (3x +5) = 49 . . . . use the given information and relation
... 5x +4 = 49 . . . . . . . . . . . simplify
... 5x = 45 . . . . . . . . . . . . . . . subtract 4
... x = 9 . . . . . . . . . . . . . . . . . divide by 5
The left side dimension is then
... 2x -1 = 2·9 -1 = 17 . . . . cm
The top dimension is
... 3x +5 = 3·9 +5 = 32 . . . . cm
The rectangle is 17 cm by 32 cm.
