Answer:
The other equation is [tex]x + y = 21[/tex]
The length and width are 13 and 8
Step-by-step explanation:
Given
[tex]Perimeter = 42[/tex]
[tex]y = x - 5[/tex]
Required
What is the other equation for the length and width?
x and y represents the length and width respectively.
The perimeter of a rectangle is calculated using:
[tex]Perimeter = 2 * (length + width)[/tex]
In this case, it is:
[tex]Perimeter = 2 * (x + y)[/tex]
Substitute 42 for perimeter
[tex]42 = 2 * (x + y)[/tex]
Divide through by 2
[tex]21 = x + y[/tex]
[tex]x + y = 21[/tex]
Required: The values of length and width
We have that:
[tex]y = x - 5[/tex]
[tex]x + y = 21[/tex]
Substitute x - 5 for y in the second equation
[tex]x + x - 5 = 21[/tex]
[tex]2x - 5 = 21[/tex]
Add 5 to both sides
[tex]2x - 5 + 5 = 21 + 5[/tex]
[tex]2x = 26[/tex]
Divide through by 2
[tex]x = 13[/tex]
Substitute 13 for x in [tex]y = x - 5[/tex]
[tex]y = 13 - 5[/tex]
[tex]y = 8[/tex]
Hence, the length and width are 13 and 8 respectively
