Posted by Maxie on Thursday, December 4, 2008 at 8:09pm.
The length of a rectangle is 8 cm greater than its width. Find the dimensions of the rectangle if its area is 105 cm.
How do I solve?
- Math - Cianán, Thursday, December 4, 2008 at 8:34pm
Area = Length*Width
Information you are given:
Area = 105cm^2
Length = width + 8
105 = (width + 8)*width
105 = width^2 + 8*width
105 = w^2 + 8w
rearranging we get a quadratic:
w^2 + 8w - 105 = 0
w^2 - 7w +15w - 105 = 0
w(w - 7) + 15(w - 7) = 0
(w - 7)(w + 15) = 0
The two possible solutions are
width = 7 or width = -15
Well, the width must be a positive measurement so we take the width = 7
So the answer is:
Width = 7
Length = 7 + 8 = 15
Hope that helps
Answer This Question
More Related Questions
- math - a rectangle is twice as long as it is wide. if both of its dimensions are...
- MATH - THE LENGTH OF A RECTANGLE IS 3M MORE THAN 2 TIMES ITS WIDTH. IF THE AREA ...
- algebra , help - Can someone help me set up the equations thanks. Directions: ...
- math - The length of a rectangle is 2 inches longer than the width. The area of ...
- math ,correction - Directions: Solve each of the following problems. Be sure to ...
- math - the length of a rectangle is 1 cm less than twice its width. the area is ...
- math - the length of a rectangle is 3 yds more than twice it width and the area ...
- Algebra/geometry - a rectangle has a width of 4 cm less than it's length. if a ...
- math - The length of a rectangle is 3 m more than double the width, and the ...
- Math - The length of a rectangle is 11 cm more than its width. The area of the ...