Respuesta :
The length and width of the rectangle is 10 m and 4.5 m respectively.
Step-by-step explanation:
Given,
The length of a rectangle is 1 m more than twice the width.
Area of the rectangle = 45 sq m
To find the length and width of the rectangle.
Formula
If the length and width of a rectangle be l and b respectively, the area will be lb.
Let, the width (b) be = x and
Length (l) = 2x+1
According to the problem,
(2x+1)x = 45
or, [tex]2x^{2} +x = 45[/tex]
or, [tex]2x^{2}+x-45 = 0[/tex]
or, [tex]2x^{2}+(10-9)x-45 = 0[/tex]
or, [tex]2x^{2}+10x-9x-45 = 0[/tex]
or, 2x(x+5)-9(x+5) = 0
or, (2x-9)(x+5) =
Hence,
2x-9 = 0 and x+5 = 0
or, x = [tex]\frac{9}{2}[/tex] and x= -5
We will take x = [tex]\frac{9}{2}[/tex] as the value of length cannot be negative.
So,
Width = 4.5 m and Length = 2×4.5+1 = 10 m
Answer: 10cm,4.5cm
Step-by-step explanation:
Let the length be x
Let the breadth be y
The length is 1m more than twice the breadth
I.e
Length = 1+ 2breadth
I.e
X=1+2y......equation 1
Area of the rectangle is
Length ×breadth
I.e area= length×breadth
45= x×y
Substitute for X=1+2y
45= (1+2y)×y
45=y+2y^2
2y2+y-45=0
Factorise
Factors of -90 that will give 1 is 10&9
So we can have -10 &+9 or +10 &-9
So we will go with +10 &-9
Substitute for it
2y2+10y-9y-45
2y(y+5)-9(y+5)
(2y-9)(y+5)
2y-9=0
2y=9
Y=9/2=4.5 or
Y+5=0
Y= -5
Substitute for y in equation 1
X= 1+2y
X=1+2(4.5)
X=1+9
X= 10 or
X= 1+2(-5)
X= 1+(-10)
X= 1-10
X= -9
The positive values will be taken,
So length which is x is 10cm
And width which is y is 4.5cm