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Answers
Answer:
Ncert solutions
Grade 8
Mathematics
Science
Chapters in NCERT Solutions - Mathematics , Class 8
Exercises in Linear Equations in One Variable
Question 2
Q2) The perimeter of a rectangular swimming pool is 154 m. Its length is 2 m more than twice its breadth. What are the length and breadth?
Solution
Transcript
Solution:
Let the breadth of the pool be x m.
Then, the length of the pool = \left(2x+2\right)(2x+2) m.
Perimeter = 2(l+b)
\Rightarrow\ 154\ =\ 2\left(2x+2+x\right)⇒ 154 = 2(2x+2+x)
\Rightarrow\ \frac{154}{2}=\frac{2\left(2x+2+x\right)}{2}⇒
2
154
=
2
2(2x+2+x)
[Dividing both sides by 2]
\Rightarrow\ 77\ =\ 3x\ +\ 2⇒ 77 = 3x + 2
\Rightarrow\ 77-2=3x+2-2⇒ 77−2=3x+2−2
[Subtracting 2 from both sides]
\Rightarrow\ 75=3x⇒ 75=3x
\Rightarrow\ \frac{75}{3}=\frac{3x}{3}⇒
3
75
=
3
3x
[Dividing both sides by 3]
\Rightarrow25=x⇒25=x
\Rightarrow\ x=\ 25\ m⇒ x= 25 m
Hence, length of the pool = 2x + 2
2 x 25 + 2 = 50 + 2 = 52 m
And, breadth of the pool = 25 m.
Answer:
perimeter = 2(l + b)
154 = 2(l + b) (1)
ACCORDING TO QUESTION
l = 2 + 2b (2)
BY SUBSTITUTING THE VALUE OF l in equation (1)
154 = 2{(2 + 2b) + b}
154/2 = 2 + 2b + b
77 = 2 + 3b
77 - 2 = 3b
75/3 = b
b = 25
BY SUBSTITUTING THE VALUE OF b IN EQUATION (2)
l = 2 + 2b
l = 2 + 2 × 25
l = 2 + 50
l = 52
THUS LENGTH AND BREADTH OF THE POOL ARE
LENGTH = 52meter
BREADTH = 25meter ans.