A partir de las informaciones de la pregunta, se encontró que el lado del primer cuadrado es igual a 7 cm.
The square is a quadrilateral that has all sides (x) equals and angles equal to 90°. The perimeter of a square is equal to the sum of sides, so, p=x+x+x+x=4x. And the area of square formula is A=x².
Therefor, the AREA 1= x².
From problem data, you can write the area 2.
AREA 2 =(x+3)*(x+3)=x²+51, then
x²+3x+3x+9=x²+51
6x=51-9
6x=42
x=7
Learn more about area of square here:
https://brainly.com/question/11239678