Question 263346
The trick is to find the sides then find the perimeter not the perimeter first.
We know that 
the side nof the square is 7 more than the side of the hexagon
s=h+7 and 
and we know that the perimeter of the square is 4s
and the hexagon is 6h
and the the two perimeters are equal
4s=6h
s=h+7
substitute h+7 for s
4(h+7)=6h
4h+28=6h
28=2h
14=h
s=h+7
s=21
h=14 s=21
check
6*14=4*21
84=84
both perimeters equal 84
ok
This problem should be in the word problem geometry category