Consider that the initial length and width of the rectangle are given as,
[tex]\begin{gathered} l=20 \\ b=20 \end{gathered}[/tex]After the length is increased by 10%, the new length (L) of the rectangle is calculated as,
[tex]\begin{gathered} L=(1+\frac{10}{100})\cdot l \\ L=(\frac{110}{100})\cdot20 \\ L=22 \end{gathered}[/tex]After the width is decreased by 10%, the new width (B) of the rectangle is calculated as,
[tex]\begin{gathered} B=(1-\frac{10}{100})\cdot b \\ B=(\frac{90}{100})\cdot20 \\ B=18 \end{gathered}[/tex]Then the area (A) of the new rectangle is calculated as,
[tex]\begin{gathered} A=L\times B \\ A=22\times18 \\ A=396 \end{gathered}[/tex]Thus, the new area of the rectangle is 396 square meters.
