Answer:
[tex]w = 17in[/tex]
Step-by-step explanation:
Given:
[tex]p=2l+2w[/tex]
[tex]l=35in[/tex]
[tex]p=84in[/tex]
We know these values, so let's plug them into the equation and solve for [tex]w[/tex].
[tex]p=2l+2w[/tex]
[tex]84=2(35)+2w[/tex]
[tex]84=70+2w[/tex]
[tex]14=2w[/tex]
[tex]w=7[/tex]