Chapter 6 - Section 6.7 - Quadratic Equations and Problem Solving - Exercise Set - Page 469: 54

6 yds

$(16-x)(24-x)=180$ $384-16x-24x+x^2=180$ $x^2-40x+204=0$ $x^2-6x-34x+204=0$ $x(x-6)-34(x-6)=0$ $(x-6)(x-34)=0$ $x-6=0$ $x=6$ $x-34=0$ $x=34$ (this is invalid since the largest dimension of the garden and the walk is 24)