Question

I dont know what is it!

Answer 1

The area of the square:
`A_S=x^2`

The area of the rectangle:
`A_R=x(x+6)`

The area of the rectangle is 4 times the areao f the square:

`A_R=4A_S`

therefore

`x(x+6)=4x^2\\\\(x)(x)+(x)(6)=4x^2\\\\x^2+6x=4x^2\ \ \ \ |-4x^2\\\\-3x^2+6x=0\\\\-3x(x-6)=0\iff-3x=0\ \vee\ x-6=0\\\\x=0\ \vee\ x=6`

a) the length of the square x = 6

`x+6=6+6=12`

b) the width of the rectangle x + 6 = 12