NCERT Solution for Class 8 Math Chapter – 2 Exercise – 2.3

Q1. Solve the following equations and check your results.

• 3x = 2x + 18

Solution:-

3x – 2x = 18

X = 18

3 x 18 = 2 x 18 + 18

54 = 54

LHS = RHS

• 5t – 3 = 3t – 5

Solution:-

5t – 3 = 3t – 5

5t – 3t = -5 + 3

2t = -2

T = -1

-5 -3 = -3 – 5

-8 = -8

LHS = RHS

• 5x + 9 = 5 + 3x

Solution:-

5x + 9 = 5 + 3x

5x – 3x = 5 – 9

2x = -4

X = -4/2

X = -2

-10 + 9 =

5 + (-6)

-1 = -1

LHS = RHS

• 4z + 3 = 6 + 2z

Solution:-

4z – 2z = 6 -3

2z = 3

Z = 3/2

( 4 x 3/2) + 3 = 6 + ( 2 x 3/2)

= 6 + 3 = 6 + 3

= 9 = 9

LHS = RHS

• 2x – 1 = 14 – x

Solution:-

2x – 1 = 14 – x

2x + x = 14 + 1

3x = 15

X = 15/3

X = 5

10 – 1 = 9

9 = 9

LHS = RHS

• 8x + 4 = 3( x – 1) + 7

Solution:-

8x + 4 = 3( x – 1 ) + 7

8x + 4 = 3x – 3 + 7

8x – 3x = -3 -4  + 7

5x = 0

X = 0

0 + 4 = 0 – 3 + 7

4 = 4

RHS = LHS

• X = 4/5 ( x + 10)

Solution:-

X = 4/5 ( x + 10)

X = 4x/5 + 40/5

X  – (4x/5) = 8

( 5x – 4x)/5 = 8

X = 8 x 5

X = 40

40 = 4/5 ( 40+10)

40 = 4/5 x 50

40 = 200/5

40 = 40

• 2x/3 + 1 = 7x/15 + 3

Solution:-

2x/3 + 1 = 7x/15 + 3

2x/3 -7x/15 = 3 – 1

= (10x – 7x)/15 = 2

3x = 2 x 15

3x = 30

X = 30/3

X = 10

2 x 10/3 + 1 = 7 x 10/15 + 3

LHS = RHS

• 2y + 5/3 = 26/3 – y

Solution:-

2y + 5/3 = 26/3 – y

= 2y + y = 26/3 – 5/3

3y = ( 26 – 5)/3

3y = 21/3

Y = 7/3

( 2 x 7/3) + 5/3 = 26/3 – 7/3

19/3 = 19/3

LHS = RHS

(X) 3M = 5M – 8/5

Solution:-

3m = 5m – 8/5

5m – 3m = 8/5

2m = 8/5

2m x 5 = 8

10m = 8 m = 10/8

M = 5/4

= 3 x (4/5) = ( 5 x 4/5) – 8/5

= 12/5 =  12/5

LHS = RHS