Question

solve this for class 8 maths ncert algebraic expressions. All 10 questions answer to be solved no wrong answers​

Answer 1

Answer:

1.x+3=5

x=5-3=>2

x=2

2.15-9x=7

-9x=7-15

x=-8/-9

x=8/9

other you slove your itself

Answer 2

Before We Start:

In all the 10 questions, we will have to find the value of the variables. This can be done by transposing the variables to the LHS and the constants to the RHS. After applying the operations as per the question, we will get the respective answers.

Answers:

1. x + 3 = 5

→ Transposing 3 to the RHS:

x = 5 - 3

x = 2

2. 15 - 9x = 7

→ Transposing 15 to the RHS:

-9x = 7 - 15

-9x = -8

→ Transposing -9 to the RHS:

$\sf{x=\dfrac{-8}{-9}}$

x = 8/9

3. 2y + 1 = 8

→ Transposing 1 to the RHS:

2y = 8 - 1

2y = 7

→ Transposing 2 to the RHS:

$\sf{y=\dfrac{7}{2}}$

y = 7/2

4. 2p - 3 = p + 2

→ Transposing -3 to the RHS and p to the LHS:

2p - p = 2 + 3

p = 5

5. 5x + 7 = 3 - x

→ Transposing 7 to the RHS and -x to the LHS:

5x + x = 3 - 7

6x = -4

$\sf{x=\dfrac{-4}{6}}$

$\sf{x=\dfrac{-2}{3}}$

x = -2/3

6. 6p = 4p + 18

→ Transposing 4p to the LHS:

6p - 4p = 18

2p = 18

$\sf{p=\dfrac{18}{2}}$

p = 9

7. 5m + 9 = 5 + 3m

→ Transposing 9 to the RHS and 3m to the LHS:

5m - 3m = 5 - 9

2m = -4

$\sf{m=\dfrac{-4}{2}}$

m = -2

8. 4y - 1 = 14 - y

→ Transposing -1 to the RHS and -y to the LHS:

4y + y = 14 + 1

5y = 15

$\sf{y=\dfrac{15}{5}}$

y = 3

9. 3m = 5m - 6

→ Transposing 5m to the LHS:

3m - 5m = -6

-2m = -6

$\sf{m=\dfrac{-6}{-2}}$

m = 3

10. 12y = 60

→ Transposing 12 to the RHS:

$\sf{y=\dfrac{60}{12}}$

y = 5

Knowledge Bytes:

 While transposing a constant or a variable with an or subtract symbol on the left, the sign changes to the exact opposite. This does not apply for multiplication and division.