Since 4z+3+3z+2 is the perimeter…
Then 4z+3+3z+2= 136
7z+3+2=136
7z+5=136
Then u move the +5 to the other side (but when u move it…. U have to change the + to a -)
Then it becomes 7z =136-5
7z= 131
Then divide 131 by 7
Z= 131/7
=18.7(round up to 3 significant figures)