# Ex.1.1 Q8 Integers - NCERT Maths Class 7

Go back to  'Ex.1.1'

## 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}

Learn from the best math teachers and top your exams

• Live one on one classroom and doubt clearing
• Practice worksheets in and after class for conceptual clarity
• Personalized curriculum to keep up with school