Download App

Rational Numbers — MATHS STD 8 — Question

Gujarat BoardEnglish MediumSTD 8MATHSRational Numbers1 Mark
MCQ
$-\frac{3}{8}+\frac{1}{7}=+\Big(\frac{-3}{8}\Big)$ is an example to show that:
  • ✓
    Addition of rational numbers is commutative.
  • B
    Rational numbers are closed under addition.
  • C
    Addition of rational number is associative.
  • D
    Rational numbers are distributive under addition.
✓

Answer

Correct option: A.
Addition of rational numbers is commutative.

 Given, $-\frac{3}{8}+\frac{1}{7}=+\Big(\frac{-3}{8}\Big)$
Let two rational number, $\text{a}=\frac{-3}{8},\ \text{b}=\frac{1}{7}$
$\therefore\text{a}+\text{b}=\frac{-3}{8}+\frac{1}{7}$
$=\frac{-21+8}{56}$
$=\frac{-13}{56}$
and
$\text{b}+\text{a}=\frac{1}{7}+\frac{-3}{8}$
$=\frac{8-21}{56}$
$=\frac{-13}{56}$
Clearly, $a + b = b + a$
So, addition is communucation for rational numbers.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q. [1 Marks Each]" from Rational Numbers→Rational Numbers — all question types→MATHS STD 8 question papers→Gujarat Board STD 8 question papers→Gujarat Board question paper generator→

Similar questions

Tick $(\checkmark)$ the correct answer of the following: Which of the following numbers is not a perfect square$?$
Hint: The number $1843$ ends in $3.$
→
How many terms are there in the expression $5xy^2?$
→
If the two adjacent angles of a parallelogram are equal, then each of its angle is?
→
Tick $(\checkmark)$ the correct answer of the following: Which of the following numbers is not a perfect square?
→
If $2 x-3=x+2$, then $x=?$
→
If one angle of a parallelogram is of $65^\circ ,$ then the measure of the adjacent angle is:
→
Factorize by grouping $15pq + 15 + 9q +25p$
→
The perimeter of a trapezium is $52\ cm$ and its each non-parallel side is equal to $10\ cm$ with its height $8\ cm$. Its area is:
→
The following pie chart represents the distribution of proteins in parts of a human body. What is the ratio of distribution of proteins in the muscles to that of proteins in the bones?
→
A geometric representation showing the relatlonship between a whole and its parts is a
→