Answer:
L=15
W=21
Step-by-step explanation:
Since it's a frame and the height is not listed, I decided that it was a normal rectangle, instead of a rectangular prism.
In this case, the equation we start with would look something like this:
315 = (17+2x)(11+2x)
2x is necessary because the frame covers the entire shape, meaning that it will apply twice, one for each end.
By simplifying this into standard form, we get:
-4x²-56x+128=0
Next, we plug this equation into the quadratic formula:
x=
(Please ignore the "A" next to 56, it wont disappear for some reason)
Through simplifying the quadratic formula, we get two answers:
x=-16
x=2
We can't use negatives, so 2 becomes what we use for X.
From here, use the following equations to solve for the corresponding lengths:
L=11+2(2)
W=17+2(2)
Answers:
L=15
W=21
Hope it helped!