Ncert solutions

Ncert solutions

Grade 7

Algebraic Expressions | Exercise 12.3

Question 9

Q1) If m\ =\ 2 , find the value of:

i) m-2

ii) 3m\ -\ 5

iii) 9-5m

iv) 3m^2-\ 2m\ -\ 7

v) \frac{5m}{2}-\ 4

Solution 1:

i) m-2

Putting m\ =\ 2

= 2-2\ =\ 0

ii) 3m\ -\ 5

Putting m-2

= 3\left(2\right)\ -\ 5\ =\ 0

iii) 9-5m

Putting m\ =\ 2

= 9-5\left(2\right)\ =\ -1

iv) 3m^2-\ 2m\ -\ 7

Putting m\ =\ 2

= 3\left(2\right)^2\ -\ 2\left(2\right)\ -\ 7

= 12\ -\ 4\ -\ 7

= 1

v) \frac{5m}{2}-\ 4

Putting m\ =\ 2

= \frac{5\left(2\right)}{2}\ -\ 4=\ 1

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Question 9

Q1) If m\ =\ 2 , find the value of:

i) m-2

ii) 3m\ -\ 5

iii) 9-5m

iv) 3m^2-\ 2m\ -\ 7

v) \frac{5m}{2}-\ 4

Solution 1:

i) m-2

Putting m\ =\ 2

= 2-2\ =\ 0

ii) 3m\ -\ 5

Putting m-2

= 3\left(2\right)\ -\ 5\ =\ 0

iii) 9-5m

Putting m\ =\ 2

= 9-5\left(2\right)\ =\ -1

iv) 3m^2-\ 2m\ -\ 7

Putting m\ =\ 2

= 3\left(2\right)^2\ -\ 2\left(2\right)\ -\ 7

= 12\ -\ 4\ -\ 7

= 1

v) \frac{5m}{2}-\ 4

Putting m\ =\ 2

= \frac{5\left(2\right)}{2}\ -\ 4=\ 1

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subject-cta
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