Solve quadratic equations

Question

You are making a rectangular table. The area of the table is 10ft^2. You want the length of the table 1ft shorter than twice it’s width. What  should the dimensions of the table be?

Answer 1

Let the width be W then the length is 2W-1. The area is 10=W(2W-1)=2W²-W.

So we get the quadratic 2W²-W-10=0=(2W-5)(W+2). We reject negative values for W so 2W-5=0, W=5/2=2.5 feet is the solution: the width is 2½ feet and the length is 4 feet.