A rectangle is ##6## units wide and ##x-8## units long. It has the same area as a triangle with a height of ##7## units and a base of ##x-3## units. What is the area of the rectangle?

Rectangle Area ##=lw## Triangle Area ##=1/2bh##

Set the two areas equal to each other, solve for x, then substitute x back into the area for the rectangle.

##6xx(x-8)=1/2xx7xx(x-3)##

Simplify ...

##6x-48=3.5x-10.5##

##2.5x=37.5##

##x=15##

Area of Rectangle ##=6xx(x-8)=6xx(15-8)=42##

[Note: 42 is also the area of the triangle]

hope that helped