Question 79660
Since the perimeter is the sum of all sides we can say:


{{{60=7y+2y+1+3y+5}}}


{{{60=12y+6}}} Combine like terms


{{{54=12y+6}}}


{{{54/12=cross(12/12)y}}}


{{{y=9/2}}}

So y is nine halves or 4.5

Check:

{{{60=7(4.5)+2(4.5)+1+3(4.5)+5}}} Plug in y=4.5

{{{60=31.5+9+1+13.5+5}}}

{{{60=60}}} works