Question 715247
The area of the rectangular plot is 140m^2. The length of the plot (in metres) is one less than three times its breadth. We have to find length & breadth pf the plot

let breadth be x
length is 3x-1

Area = {{{140 m^2}}}

Area of rectangle = L * B

140 =x(3x-1)

{{{140 = 3x^2-x}}}

{{{3x^2-x-140=0}}}

Find the roots of the equation by quadratic formula							
			-1				
a=	3	b=	-1	c=	-140		
			-1680				
b^2-4ac=	1	-					
b^2-4ac=	1681			{{{sqrt(	1681	)}}}=	41
{{{x=(-b+-sqrt(b^2-4ac))/(2a)}}}							
{{{x1=(-b+sqrt(b^2-4ac))/(2a)}}}			41				
x1=(	1	+		)/	6		
x1=	7		) /				
x2=(	1	-41		6			
x2=	-6.67						
Ignore negative value			mph				
x	=	7					

breadth = 7
length = 3(7) -1= 20

The dimensions are 7 & 20 m