Need help please!!! thanks!!!

Question

If the perimeter of a rectangle is 36 cm and the area is 77 square cm, then what are the dimensions of the rectangle?

Answer 1

P=2l+2w

36=2l+2w

18=l+w

l=18-w

A=l*w

77=(18-w)*w

77=18w-w^2

w^2-18w+77=0

(w-7)(w-11)=0

w-7=0

w=7

w-11=0

w=11

the rectangle is 7 cm by 11 cm

you should see that you could have solved the problem by simple arithmetic...

36/2=18 (half of the perimeter)

18=7+11 and 7*11=77, or...

77=7*11 and 7+11=18