I have to solve by system of equations

Question

Danny wants to build a garden area in his back yard. He forms the garden in the shape of a rectangle . The perimeter of the rectangle is 84 feet. The length is 6 feet more that the width. Find the length and the width of Danny's garden 

Answer 1

Leah,

 

Use W and L as the answers (quantities) for which we are solving.

 

Perimeter = P = L + W = 84

 

Length = L = W + 6   [...6 feet more than...]

 

Substitute L into the equation for the perimeter:

 

P = L + W = (W + 6) + W = 84

 

Combine terms for W:

 

2W + 6 = 84

 

2W + 6 - 6 = 84 - 6 = 78

 

2W = 78

 

2W/2 = 78/2

 

W = 39

 

Substitute this value for W into the equation for length:

 

L = W + 6 = 39 + 6 = 45

 

Check your answer substituting into the equation for the perimeter:

 

P = 84 = L + W = 45 + 39 = 84!

 

Michael.