Answer:
The dimensions of poster are 32.5 in wide and 40.5 in tall.
Step-by-step explanation:
Given:
A poster is 8 in taller than it is wide.
It is mounted on a backing board that provides a 2 in border on each side of the poster.
The area of the backing board is 308 in².
Now, to find the dimensions of the poster.
Let [tex]x[/tex] be the length of the poster.
And [tex]y[/tex] be the width of the poster.
As given, poster is 8 in taller than it is wide.
So,
[tex]x=y+8[/tex] ......(1)
Area = 308 in².
So, it is mounted on a backing board that provides a 2 in border on each side of the poster.
According to question:
[tex]2\times (2(y+4))+2\times (2\times x)=308[/tex]
Now. substituting the value from equation (1) in the place of [tex]x[/tex] we get:
[tex]2\times (2y+8)+2(2\times (y+8))=308[/tex]
[tex]2\times (2y+8)+2(2y+16)=308[/tex]
[tex]4y+16+4y+32=308[/tex]
[tex]8y+48=308[/tex]
Subtracting both sides by 48 we get:
[tex]8y=260[/tex]
Dividing both sides by 8 we get:
[tex]y=32.5\ in.[/tex]
The width of the poster = 32.5 in.
Now, substituting the value of [tex]y[/tex] in equation (1):
[tex]x=y+8[/tex]
[tex]x=32.5+8[/tex]
[tex]x=40.5\ in.[/tex]
Length of the poster = 40.5 in.
Therefore, the dimensions of poster are 32.5 in wide and 40.5 in tall.