Ex.1.1 Q8 Integers - NCERT Maths Class 7

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Question

Verify \(a– (–b) = a + b\) for the following values of \(a\) and \(b\)

(i)  \(a=21, \quad b=18\)

(ii)  \(a= 118, \quad b =125\)

(iii)  \(a =75, \quad b=84\)

(iv) \(a= 28, \quad b =11\)

 Video Solution
Integers
Ex 1.1 | Question 8

Text Solution

What is known?

Different value of \(a\) and \(b\).

What is unknown?

To verify: \(a-(-b)=a+b.\)

Steps:

Let,  \(a-(-b)=a+b. \)   (equation  1)

i) \(a = 21, b = 18\)
put the values of \(a\) and \(b\) in equation (1).

\[\begin{align}a-( -b)&= a + b\\ & =21-( -18)\\& = 21 + 18\\&= 21 + 18\\&= 21 + 18\\ 39 &= 39\\\rm{LHS}&= \rm{RHS}\,\,\text{(Hence Verified.)}\end{align}\]

ii) \(a= 118, b = 125\)

put the value of \(a\) & \(b\) in equation (1).

\[\begin{align}a-(-b)&= a + b\\ & =118-(-125)\\&=118 +125\\&= {118+ 125}\\&=118 + 125\\ 243 &=243\\\rm{LHS}&= \rm{RHS}\,\,\text{(Hence Verified.)}\end{align}\]

iii) \(a= 75, b= 84\)

put the value of \(a\) & \(b\) in equation (1).

\[\begin{align}a-(-b)&= a + b\\ & =75-(-84) \\&=75 + 84\\&=75+ 84\\&=75 + 84\\ 159 &= 159\\\rm{LHS}&= \rm{RHS}\,\,\text{(Hence Verified.)}\end{align}\]

iv) \(a=28 ,b=11\)

put the values of \(a\) & \(b\) in equation (1).

\[\begin{align}a-(-b)&= a + b\\ & =28-(-11)\\&=28 + 11\\&= 28+ 11\\&=28 + 11\\ 39 &= 39\\\rm{LHS}&= \rm{RHS}\,\,\text{(Hence Verified.)}\end{align}\]

 

 

 

 

 

 

  
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