Answer:the original length of the rectangle is 15cm
the original width of the rectangle is 5 cm
Step-by-step explanation:
Let L represent the original length of the rectangle.
Let W represent the original width of the rectangle.
A rectangle is three times as long as it is wide. This means that
L = 3W
If it's length and width are both decreased by 2 cm, it's area is decreased by 36 cm. This
(L - 2)(W - 2) = LW - 36
LW - 2L - 2W + 4 = LW - 36
LW - LW - 2W - 2L = - 36 - 4
- 2L - 2W = - 40 - - - - - - - - - -1
Substituting L = 3W into equation 1, it becomes
- 2(3W) - 2W = - 40
- 6W - 2W = - 40
- 8W = - 40
W = - 40/- 8 = 5
L = 3W = 3 × 5 = 15
