# Ex.1.3 Q3 Integers Solution - NCERT Maths Class 7

Go back to  'Ex.1.3'

## Question

i) For any integer $$a,$$ what is $$\left( {-1} \right) \times a$$ equal to?

ii) Determine the integer whose product with $$(–1)$$ is

(a) $$-22$$

(b) $$37$$

(c) $$0$$

Video Solution
Integers
Ex 1.3 | Question 3

## Text Solution

Steps:

(i) $$\left( {{\rm{-1}}} \right){{ a}}\,{{ = }}\,{{-a}}$$ where $$a$$ is any integer

(ii) a) $${{? \times }}\left( {{\rm{-1}}} \right){\rm{ = -22}}$$

Let $$x$$ be the required integer

\begin{align}x \times \left( {-1} \right) &= -22\qquad \dots\left( 1 \right)\\-x &= -22\\x &= 22\end{align}

Putting the value of $$x$$ in equation ($$1$$), we get

\begin{align}x \times \left( {-1} \right) = -22\\22 \times \left( {-1} \right) = -22\end{align}

b) $$? × (–1) = 37$$

Let $$y$$ be the required integer

\begin{align}y \times \left( {-1} \right)&= 37\dots(1)\\-y &= {\rm{ }}37\\y &= -{\rm{ }}37 \end{align}

Putting the value of $$y$$ in equation (1), we get

$–37 × (–1) = 37$

c) $$? × (–1) =0$$

Let $$z$$ be the required integer

\begin{align}z \times \left( {-1} \right) = 0 & \left( 1 \right)\\-z = 0\\z = 0\end{align}

Putting the value of z in equation ($$1$$), we get

\begin{align}0 × (–1) = 0\\ ? × (–1) =0 \\0 × (–1) =0 \end{align}

(Multiplying any number by $$0$$, we get the product $$0$$)

Hence (c) $$0$$ is required integer.

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