If w = width, then length = w + 20
w(w+20) = 8000
Solve for w, then length.
A rectangular garden is 20 ft longer than it is wide. Its area is 8000 ft{}^2. What are its dimensions?
Let "w" equal the width
w+20=8000
w^2+20=8000
not sure how to continue
5 answers
you have the right idea, but you should have said
w(w+20) = 8000
w^2+20w = 8000
w^2+20w-8000 = 0
(w-80)(w+100) = 0
...
w(w+20) = 8000
w^2+20w = 8000
w^2+20w-8000 = 0
(w-80)(w+100) = 0
...
How do I isolate w ?
so w=80 and w=-100 ?
If two numbers multiply to produce a product of zero, then one of them must be zero.
So, if (w-80)(w+100)=0, then either
w-80 = 0
w=80
or
w+100 = 0
w = -100
Now pick the value that makes sense for this problem. Then check your conclusion by plugging in the value and seeing whether it produces a rectangle of the correct area.
So, if (w-80)(w+100)=0, then either
w-80 = 0
w=80
or
w+100 = 0
w = -100
Now pick the value that makes sense for this problem. Then check your conclusion by plugging in the value and seeing whether it produces a rectangle of the correct area.
2 answers