Question

if the sides of a square are lengthened by 3 m, the area becomes 81 m2. Find the length of a side of the original square.

Answer 1

The length of a side of the original square is 6 meters

Explanation:

Let

x ----> the length side of the original square

The area of a square is equal to

`A=b^2`

where

b is the length side of the square

In this problem

The new length side of the square is
`b=(x+3)\ m` and the area is
`A=81\ m^2`

so

`(x+3)^2=81`

solve for x

take square root both sides

`(x+3)=9`

`x=9-3=6\ m`