Chapter 8 - Section 8.1 - Systems of Linear Equations: Substitution and Elimination - 8.1 Assess Your Understanding - Page 556: 58

The length is $775$ meters, the width is $725$ meters.

Let x=width, y=length, in meters. Perimeter:$\qquad 2x+2y=3000$ Given:$\qquad y-x=50\qquad\Rightarrow\qquad y=x+50\qquad$(*) Substitute (*) into $2x+2y=3000$ $2x+2(x+50)=3000$ $2x+2x+100=3000$ $4x=2900$ $x=725$ Back-substitute into (*) $y=725+50=775$ The length is $775$ meters, the width is $725$ meters.