Answer:
[tex]Area=15x^2[/tex] square units.
Step-by-step explanation:
The given rectangle has the following dimension:
[tex]l=5x[/tex]
and
[tex]w=3x[/tex]
The area of a rectangle is
[tex]Area=l\times w[/tex]
We substitute the dimensions in terms of [tex]x[/tex] into the formula for the area to get;
[tex]Area=(5x)\times (3x)[/tex]
This simplifies to give us;
[tex]Area=15x^2[/tex] square units.