Area is found by multiplying the length by the width.
Let X = width.
The length is x +3 ( 3 cm longer than the width).
Now you have area = x * x+3
Area is given as 754 square cm.
754 = x * x+3
Simplify:
754 = x^2 +3x
Subtract 754 from both sides:
x^2 +3x - 754 = 0
Factor:
(x -26) (x+29)
Solve for x:
x = 26 and -29.
Since the dimension cannot be negative, x = 26.
The width = 26 cm.
The length = 26 +3 = 29 cm.
Multiply each dimension by 100 to get millimeters:
Width = 260 mm
Length = 290 mm