3/5x+1/2y=30 please help!

X=50-1/2y
y=60-3/5x
x=50-1/2(60-3/5x)
x=50-30+3/5x
x=20+3/5x
2/5x=20
x=50
3/5(50)+1/2y=30
30+1/2y=30
1/2y=0
y=0
y=60-3/5(50-1/2y)
y=60-30+3/10y
y=30+3/10y
7/10y=30
300/7=y
3/5x+1/2(300/7)=30
3/5x+150/7=30
3/5x=60/7
x=100/7
SOLUTIONS ARE X=100/7, 50  Y=300/7, 0

First you  would take 9 x 4 because there is four sides to a 3D piece of wood and then you would add the two 1's x 2 because you have two ends of 1 square inch each then, you would take the 5 and multiply it by 4 because you have four sides to a 3D piece of wood and add the two 1's x 2  because you have two ends of 1 square inch each  and then add all of it together and you have your answer so it should look something like this ... 9 x 4 +2 +2 + 5 x 4 +2 + 2 = a total of 64 inches