If the perimeter of the rectangle at right is $112$ cm, which equation below represents this fact? Once you have selected the appropriate equation, solve for $x$. 

1. $(2x−7)+(4x+3)=112$

2. $4(2x−7)=112$

3. $2(2x−7)+2(4x+3)=112$

4. $(2x−7)(4x+3)=112$