### Home > GC > Chapter 1 > Lesson 1.1.3 > Problem1-25

1-25.

Read the Math Notes box for this lesson, which describes how to find the area and perimeter of a shape. Then examine the rectangle at right. If the perimeter of this shape is $120$ cm, which equation below represents this fact? Once you have selected the appropriate equation, solve for $x$.

 $\space$interior rectangle$\space$ right edge$2x+5$ bottom edge$6x-1$
1. $2x+5+6x-1=120$

1. $4(6x-1)=120$

1. $2(6x-1)+2(2x+5)=120$

1. $(2x+5)(6x-1)=120$

• The equation for the perimeter is part (c).

$\begin{array}{r} 2(6x-1)+2(2x+5)=120\\ (12x-2)+(4x+10)=120\\ 16x+8=120 \\ 16x=112 \\ x=7 \quad \end{array}$