The length of a rectangle is 2 centimeters less than twice the width. If the area is 84 square centimeters how do you find the dimensions of the rectangle?
width = 7 cm
length = 12 cm
It is often helpful to draw a quick sketch.
Let length be
Let width be
Subtract 84 from both sides
I take one look at this and think: 'can not spot how to factorise so use the formula.'
So for our equation we have: