Given:
A photograph is 3 cm longer than it is wide.
Its area is 40 square cm.
To find:
The length and width.
Step-by-step explanation:
It is given that,

Using the formula for the area of the rectangle,

Solving for w we get,

The width can not be negative.
So, the width is 5cm and the length is,

Final answer:
The width is 5cm and the length is 8cm.