contestada

A rectangle has a length of x + 4 centimeters and a width of x centimeters. The perimeter of the rectangle is 28 centimeters. What is the value of x?

Respuesta :

The perimeter=2(length+width)
length+width=perimeter/2
x+4+x=28/2
2x+4=14
2x=10
x=5
the formula for perimeter is p = 2L + 2w

plug the length and width

2(x + 4) + 2 (x) = 28 

2x + 8 + 2x = 28

add like terms in one side

4x + 8 = 28
     -8     -8

4x = 20

divide by 4

x = 5