Determine the length and breadth of a rectangle if the length is 3cm less than twice the breadth, and the perimeter is 18 .
Set up two equations.
2L + 2W = 18
L = 2W - 3
Now, substitute L into the first equation to find W.
2L + 2W = 18
2(2W - 3) + 2W = 18
4W - 6 + 2W = 18
6W - 6 = 18
6W = 24
W = 4 cm
Next, put in the value of W into any of the equations to get L.
L = 2W - 3
L = 2(4) - 3
L = 8 - 3
L = 5 cm