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NCERT Solutions for Linear equations Class 8 Mathematics Chapter 2 Exercise 2.3




In this page we have NCERT Solutions for Linear equations Class 8 Mathematics for Exercise 2.3 . Hope you like them and do not forget to like , social share and comment at the end of the page.
Tips for this NCERT Exercise
1) Validation or check result means to verify the answer by putting the values in the linear equation
2) Calculate the LHS(Left Hand side) by substituting the variable and similary calculate the RHS(Right hand side) by substituting the variable
3) Both the LHS and RHS should be equal
Question 1
Solve and check result: 3x = 2x + 18
Answer
 3x = 2x + 18
Transposing 2x to L.H.S, we obtain
3x − 2x = 18
x = 18
Let us evaluate both the LHS and RHS for validate the answer
L.H.S = 3x = 3 × 18 = 54
R.H.S = 2x + 18 = 2 × 18 + 18 = 36 + 18 = 54
L.H.S. = R.H.S.
It proves that result is correct
Question 2
 Solve and check result: 5t − 3 = 3t − 5
Answer
5t − 3 = 3t − 5
Transposing  3t to L.H.S and −3 to R.H.S, we obtain
5t − 3t = −5 − (−3)
2t = −2
Dividing both sides by 2
t = −1
Let us evaluate both the LHS and RHS for validate the answer
L.H.S = 5t − 3 = 5 × (−1) − 3 = −8
R.H.S = 3t − 5 = 3 × (−1) − 5 = − 3 − 5 = −8
L.H.S. = R.H.S.
It proves that result is correct
Question 3
Solve and check result
 5x + 9 = 5 + 3x
Answer
 5x + 9 = 5 + 3x
Transposing 3x to L.H.S and 9 to R.H.S, we obtain
5x − 3= 5 − 9
2x = −4
Dividing both sides by 2, we obtain
= −2
Let us evaluate both the LHS and RHS for validate the answer
L.H.S = 5x + 9 = 5 × (−2) + 9 = −1
R.H.S = 5 + 3x = 5 + 3 × (−2)  = −1
L.H.S. = R.H.S.
It proves that result is correct
Question 4
 Solve and check result:
4z + 3 = 6 + 2z
Answer
 4z + 3 = 6 + 2z
Transposing 2z to L.H.S and 3 to R.H.S, we obtain
4z − 2z = 6 − 3
2z = 3
Dividing both sides by 2, we obtain
z=3/2
Let us evaluate both the LHS and RHS for validate the answer
L.H.S = 4z + 3 = 4 × (3/2) + 3 = 6 + 3 = 9
R.H.S = 6 + 2z = 6 + 2 × (3/2) = 6 + 3 = 9
L.H.S. = R.H.S.
It proves that result is correct
Question 5
 Solve and check result:
 2x − 1 = 14 − x
Answer
 2x − 1 = 14 − x
Transposing x to L.H.S and 1 to R.H.S, we obtain
2x + x = 14 + 1
3x = 15
Dividing both sides by 3, we obtain
x = 5
Let us evaluate both the LHS and RHS for validate the answer
L.H.S = 2x − 1 = 2 × (5) − 1 = 10 − 1 = 9
R.H.S = 14 − x = 14 − 5 = 9
L.H.S. = R.H.S.
It proves that result is correct


Question 6
Solve and check result:
8x + 4 = 3(x − 1) + 7
Answer
 8x + 4 = 3(− 1) + 7
8x + 4 = 3x − 3 + 7
Transposing 3x to L.H.S and 4 to R.H.S, we obtain
8− 3x = − 3 + 7 − 4
5x = − 7 + 7
5x=0
x=0
Let us evaluate both the LHS and RHS for validate the answer
L.H.S = 8x + 4 = 8 × (0) + 4 = 4
R.H.S = 3(x − 1) + 7 = 3 (0 − 1) + 7 = − 3 + 7 = 4
L.H.S. = R.H.S.
It proves that result is correct
Question 7- 
Solve and check result: NCERT Solutions for Linear equations Class 8 Mathematics Chapter 2
Answer
NCERT Solutions for Linear equations Class 8 Mathematics Chapter 2
Multiplying both sides by 5, we obtain
5x = 4(x + 10)
5x = 4x + 40
Transposing 4x to L.H.S, we obtain
5x − 4x = 40
x = 40
Let us evaluate both the LHS and RHS for validate the answer
L.H.S = x = 40
R.H.S = = 40
L.H.S. = R.H.S.
It proves that result is correct
Question 8
Solve and check result: NCERT Solutions for Linear equations Class 8 Mathematics Chapter 2 Exercise 2.3
Answer
NCERT Solutions for Linear equations Class 8 Mathematics Chapter 2 Exercise 2.3
Transposing  7x/15 on LHS and 1 on RHS
NCERT Solutions for Linear equations Class 8 Mathematics Chapter 2 Exercise 2.3
Multiplying by 15 on both sides
10x-7x= 30
3x=30
Dividing by 3 on both the sides
x=10
Let us evaluate both the LHS and RHS for validate the answer
L.H.S =NCERT Solutions for Linear equations Class 8 Mathematics Chapter 2 Exercise 2.3 =23/3
R.H.S=NCERT Solutions for Linear equations Class 8 Mathematics Chapter 2 Exercise 2.3 =23/3
L.H.S. = R.H.S.
It proves that result is correct
Question 9
 Solve and check result
NCERT Solutions for Linear equations Class 8 Mathematics Chapter 2 Exercise 2.3
Answer
NCERT Solutions for Linear equations Class 8 Mathematics Chapter 2
Transposing y to L.H.S and 5/3 to R.H.S, we obtain
NCERT Solutions for Linear equations Class 8 Mathematics Chapter 2
3y=21/3
3y=7
Dividing both sides by 3, we obtain
y=7/3
Let us evaluate both the LHS and RHS for validate the answer
NCERT Solutions for Linear equations Class 8 Mathematics Chapter 2
L.H.S. = R.H.S.
It proves that result is correct
Question 10
 Solve and check result:
NCERT Solutions for Linear equations Class 8 Mathematics Chapter 2
Answer
NCERT Solutions for Linear equations Class 8 Mathematics Chapter 2
Transposing 3m to R.H.S and 8/5 to L.H.S
8/5= 2m
Dividing both sides by 2
m=4/5
Let us evaluate both the LHS and RHS for validate the answer
L.H.S =  3m=12/5
R.H.S = 5m –(8/5)=12/5
L.H.S. = R.H.S.
It proves that result is correct

Practice similar type questions

1) Solve and check the result for 4n +7 = 23
2) Solve and check the result 3x 4 = 1 2 x
3) Solve and check the result $ \frac {m}{2} -11= 2$
4) Solve and check the result $ 11y =6y - \frac {1}{3}$
5) Solve the check the result $ \frac {x}{5} + 8=30}

Download Linear equation Exercise 2.3 as pdf




Class 8 Maths Class 8 Science