the length of a rectangle is 3 more than twice its width. the total area of the rectangle is 54 square units. what is the width and length of the rectangle? report an error



Answer :

Answer:

  • width: 4.5 units
  • length: 12 units

Step-by-step explanation:

You want to know the width and length of a rectangle with an area of 54 square units when the length is 3 more than twice the width.

Area

The formula for the area of a rectangle is ...

  A = LW

The problem statement tells us L = 2W+3, so the given values let us write the equation ...

  54 = (2W +3)W

Solution

Rewriting this a bit, we have ...

  2W² +3W -54 = 0

We can factor this if we find two integers whose product is 2(-54) = -108, and whose sum is +3. Those are 12 and -9.

  (2W -9)(2W +12)/2 = 0

  (2W -9)(W +6) = 0

Solutions are values of W that make the factors zero:

  2W -9 = 0   ⇒   W = 9/2 = 4.5

  W +6 = 0   ⇒   W = -6

The width cannot be negative, so the solution is ...

  W = 4.5

  L = 2(4.5) +3 = 12

The rectangle is 4.5 units wide and 12 units long.