Eleonore S.

February 12, 2002

Period 1

 

Computer Problem #1 

 

 

The perimeter of a rectangle is 390 inches. The length is twice the width. Find the length and width of the rectangle.

 

Length is twice width: length=2x

Width is x: width=x

Perimeter is 390 so the equation must equal 390.

 

Equation:

1          2(2x)+2(x)=390 you would times each side by 2 because there are 4 sides in a rectangle

 

2          4x+2x=390 is now becomes 4x+2x because I used associative property.

 

3          6x=390 it now becomes 6x because you combined 2 and 4.

 

4          6x/6=390/6  you divide 6 from each side so you can get x by itself

 

5        x=65 the answer is 65

 

new length=2x=2*65=130

new width=x=65

 

check:

 

2(2*65)+2(65)=390 you put in your answer to have both sides equal each                                                               other

2(130)+130=390

260+130=390

390+390          yes they equal each other and the correct answer is 65.