SOLUTION: I am trying to help my 7th grade son and I can't when I don't remember how to do it. Here is the problem. A rectangle has a perimeter of 52inches. A) Write an equation descr

Algebra ->  Linear-equations -> SOLUTION: I am trying to help my 7th grade son and I can't when I don't remember how to do it. Here is the problem. A rectangle has a perimeter of 52inches. A) Write an equation descr      Log On


   

Question 273838: I am trying to help my 7th grade son and I can't when I don't remember how to do it. Here is the problem.
A rectangle has a perimeter of 52inches.
A) Write an equation describing the possible values of x and y
B) Use the intercepts from the equation to graph
C) Give 3 pairs of whole-numbers values of x and y that could represent side lengths of the rectangle.
Please show me all the steps so I can help him.
Thanks
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
If x and y are the lengths of the sides in inches, and
p = perimeter
The formula is:
p+=+2x+%2B+2y
given:
p+=+52 in
2x+%2B+2y+=+52
subtract 2x from both sides
2y+=+-2x+%2B+52
divide both sides by 2
y+=+-x+%2B+26
I'll plot this line
+graph%28+500%2C+500%2C+-5%2C+30%2C+-5%2C+30%2C+-x+%2B+26%29+
Any point (x,y) on this line is a solution to 2x+%2B+2y+=+52
----------------------------------------------
I can find 3 whole-number solutions by trying different x's
and finding the y's
I'll try x+=+8
y+=+-8+%2B+26
y+=+18
so, (8,18) is a solution
I'll try x+=+16
y+=+-16+%2B+26
y+=+10
so, (16,10) is a solution
I'll try x+=+13
y+=+-13+%2B+26
y+=+13
so, (13,13) is a solution
Notice that you can't make either x or y zero,
since you wouldn't have a rectangle anymore, just
a straight line