The perimeter, P, of a rectangle is the sum of twice the length and twice the width. P= 21+ 2w units P= 2([+w) units P= 2(x+3) units P= 2(5)-2(9) units P= 4 x units

Respuesta :

We can see the problem states that P = 2(x+3) and also states that P=4x

Those equations lead to the expression

2(x+3)=4x

Operating

2x+6=4x

Subtracting 2x

6 = 2x

Solving for x

x = 6/2 = 3

Thus, the perimeter is

P = 2(3+3) = 12 units