SOLUTION: A rectangle is twice as long as it is wide. If the length and width are each decreased by 4cm, the area is reduced by224cm squared. Find the dimensions of the original rectangle.
Algebra.Com
Question 58533: A rectangle is twice as long as it is wide. If the length and width are each decreased by 4cm, the area is reduced by224cm squared. Find the dimensions of the original rectangle.
Found 2 solutions by checkley71, ankor@dixie-net.com:
Answer by checkley71(8403) (Show Source): You can put this solution on YOUR website!
L=2W
(2W-4)*(W-4)=2W*W-224
THUS
2W^2-12W+16=2W^2-224
2W^2-2W^2-12W+16=224=0
-12W+240=0
-W+20=0
-W=-20
W=20 IS THE WIDTH
L=2*20
L=40 IS THE LENGTH
PROOF
(40-4)(20-4)=40*20-224
36*16=800-224
576=576
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
A rectangle is twice as long as it is wide.
x = width; 2x = length
:
If the length and width are each decreased by 4cm,the area is reduced by 224 cm squared.
Original area = 2x^2
:
New dimensions: (x-4; (2x-4); new area given as 2x^2 - 224
:
2x^2 - 224 = (x-4)*(2x-4)
:
2x^2 - 224 = 2x^2 - 12x + 16
:
2x^2 - 2x^2 + 12x = 16 + 224
:
12x = 240
x = 240/12
x = 20
:
Find the dimensions of the original rectangle.
x = 20cm is the width; 40 cm is the length
:
:
Check:
20*40 = 800 sq cm
16*36 = 576 sq cm
---------------------subtract
>>>>>>>>>224 sq cm
RELATED QUESTIONS
A rectangle is twice as long as it is wide. If its length and width are each reduced by 1 (answered by amoresroy)
A rectangle is twice as long as it is wide. If the length is decreased by 4 inches and... (answered by dfrazzetto)
A rectangle is twice as long as it is wide. If its length is decreased by 4 and its... (answered by orca)
A rectangle is three times as long as it is wide. If its length and width are both... (answered by josgarithmetic)
A rectangle is twice as long as it is wide. If it’s length and width are both decreased... (answered by Alan3354)
A rectangle is twice as long as it is wide. If its length and width are both decreased by (answered by ankor@dixie-net.com)
A rectangle is twice as long as it is wide. If its length and width are both decreased... (answered by mananth)
A rectangle is three times as long as it is wide. if its length and width are both... (answered by ankor@dixie-net.com)
A rectangle is half as wide as it is long. If both the length and width are decreased by (answered by MathTherapy)