Question 118528
5m is correct, but what was your technique?


the lawn is 30 by 40 or 1200 sq m, so half would be 600 sq m


(30-2x)(40-2x)=600 ___ 1200-140x+4x^2=600 ___ 600-140x+4x^2=0


x^2-35x+150=0 ___ (x-30)(x-5)=0