Question

The length of the rectangle is $2m-1$ and the breadth of the rectangle is $7m-9$. Find the expression for the perimeter of the rectangle.

• A. $9m-10$
• B. $18m-20$
• C. $(2m-1)(7m-9)$
• D. None of these

Answer 1

The correct option is B $18m-20$

We are given with a rectangle whose length is $2m-1$ and breadth is $7m-9$. This rectangle can be shown as


Perimeter of the rectangle $=2\times (Length+Breadth)$
$=2\times (2m-1+7m-9)$

Combining the like terms:
$=2\times \left[\right(2m+7m)-(1+9\left)\right]$
$=2\times (9m-10)$
$=18m-20$

Perimeter of the rectangle $=18m-20$
Therefore, option (b.) is the correct answer.