Question 8628
You know the garden is 10 x 16 = 160 sq. ft.
You know the garden is increased in both directions by x feet.
So the new area is (10+x)(16+x) and now equals 200 sq. ft. [Why?]
So the final equation is {{{x^2+26x+160=200}}} or {{{x^2+26x-40=0}}}
Solving this gives an answer near 1.37