An achitect is allowed 15 square yards of floor space to add a small bedroom to a house. Because of the room design in relationship to the existing structure, the width of the rectangular floor must be 7 yards less than two times the length. Find he length and width of the rectangular floor that the architect is permitted.

Question

anonymous · Answer

we just solved it

anonymous · Answer

if l is the length, then the width is 2l-7
the area is 15
so l(2l-7)=15

anonymous · Answer

huh? no. the answer is l =5yards and width = 3 yards

anonymous · Answer

solve the quadratic equation I posted.

anonymous · Answer

my bad. didn't subtract the 15

anonymous · Answer

$$2l ^{2}-7l-15=0$$$$(2l+3)(l-5)=0$$$$\therefore l=5,(-3/2)$$(-3/2) is extraneous, so $$length=5$$ and $$width =5\times2-7=3$$