SOLUTION: The area of a grassy plot is 480 metres. If each side had been 5m longer, the area would have been increased by 245 square metres. Find the length of the fence to surround it.

Question 560291: The area of a grassy plot is 480 metres. If each side had been 5m longer, the area would have been increased by 245 square metres. Find the length of the fence to surround it.
Answer by mananth(16946) (Show Source): You can put this solution on YOUR website!
let the length be x
width = y
xy=480
x=480/y
(x+5)(y+5) is the area after increasing the sides
xy+5x+5y+25
xy+5x+5y+25- xy = 245
5x+5y=245-25
5x+5y=225
x+y=45
480/y +y = 45
multiply equation by y
480 +y^2=45y
y^2-45y+480=0
Find the roots of the equation by quadratic formula

a= 1 , b= -45 , c= 480

b^2-4ac= 2025 + -1920
b^2-4ac= 105

x1=( 45 + 10.25 )/ 2
x1= 27.62
x2=( 45 -10.25 ) / 2
x2= 17.38
sides are 27.62 & 17.38m

The Perimeter=2*( 27.62 + 17.38)
= 90 meters
RELATED QUESTIONS
the length of a room exceeds its breath by 8dm. If each had been increased by 2dm the... (answered by ewatrrr)

An engineer was told that a survey had been made on a certain rectangular field but the... (answered by josmiceli)

Each side of a square have been increased by 20% soto make a big square.Find the... (answered by fractalier)

the length of a room exceeds its breath by 3dm. If the length of a room had been... (answered by ikleyn)

A small rectangular vineyard is to have an overall dimension of 100 feet by 200 feet.... (answered by josgarithmetic)

The area of a rectangular hall is 48 square metres. If the length and breadth be... (answered by josgarithmetic,advanced_Learner,MathTherapy)

when each side lenth of square is increased 10 inches the resulting areas is four times... (answered by ankor@dixie-net.com)

the length of a room exceeds its breath by 3dm. If the length of a room has been... (answered by ikleyn)

If each side of a square be increased by 10% the percentage increase in area... (answered by Fombitz)