The width of a rectangle is 12cm less than the length. the perimeter is 156cm. find the width and length

Step-by-step explanation:

Let W and L represent the width and length (in cm), respectively. The perimeter length is twice their sum, so we have ...

  2(W +L) = 156

  W = L -12

Substituting the second equation into the first, we have ...

  2(L -12 +L) = 156

  4L -24 = 156 . . . . . . . simplify

  4L = 180 . . . . . . . . . . .add 24

  L = 45 . . . . . . . . . . . . divide by 4

  W = 45 -12 = 33 . . . . use the expression for W to find its value

The width is 33 cm, and the length is 45 cm.