A rectangle is 6cm longer than it is wide.
If its area is the same as that of a square of side 4cm find its dimensions.

Let the length be l and the width be w.

The length is longer than the width by 6, meaning:

l = w + 6

The area is the same as that of a square of side 4 cm. Can you find that area?

Then, you will know the area of the rectangle. Recall that the area of a rectangle is given by the product of the length and the width.

You will get two equations from that which you can go forward with simultaneous equations.