the length of a rectangle is 4 units longer than its width. if the area is 126 square units find the length and width?

Question

How to find the answer and I don't know how to solve its please help me.

Answer 1

I agree with Melinda's analysis. 

 

To complete the problem for you,

 

126 square units (the Area) = Width (call it W units)  x   (4 + W) (the Length in units)

 

126 = W x (4+W)

126 = 4W  + W^2

or W^2 + 4W -126 = 0

Using the quadratic formula, W = -4 +/-  [ 16 - (4)(1)(-126)] ^1/2,   all divided by 2

                                          W =  -4 +/- (504)^1/2, all divided by 2

                                         W =  -4 +/- 22.804, all divided by 2

                                         W = 9.40 units (the answer of -13.40 is nonsense, of course)

 

Answer 2

The area of a rectangle is length times width:

 

A=L*W

 

We know that the area is 126 square units.

 

A=126

 

We also know that the length is 4 units longer than its width.

 

L=4+W

 

Now plug in the area and length into the equation

 

A=L*W

 

and solve for the width.