91Ó°ÊÓ

Real numbers are simply the combination of Whole numbers, Integers, Rational and Irrational numbers in the number system.

Suppose a, b, and c is three real numbers.

Distributive Property of Multiplication

Property: $-\text{a}  \text{(b}  -  \text{c}  \text{)}  =  (-\text{a} ) ·  \text{b} -  (-\text{a} ) ·  \text{c} $

Example: $-\text{3}  \text{(8}  -  \text{5}  \text{)}  =  (-\text{3} ) ·  8 -   (-\text{3} ) ·  \text{5}  =  -24+15=-  9$

We know that double negative is always positive. $(-  3  ) ·  (-  7  )  =21$

Distributive Property of Multiplication

Property: $-\text{a}  \text{(b}  -  \text{c}  \text{)}  =  (-\text{a} ) ·  \text{b} -  (-\text{a} ) ·  \text{c} $

$\begin{array}{l}−\text{ â¶Ä‰}3(−\text{ â¶Ä‰}7\text{ }+\text{ }2x)=\text{ â¶Ä‰}(−\text{ â¶Ä‰}3\text{ â¶Ä‰})\text{ }·\text{ â¶Ä‰}(−\text{ â¶Ä‰}7\text{ â¶Ä‰})+\text{ â¶Ä‰}(−\text{ }3)\text{ â¶Ä‰}·\text{ â¶Ä‰}2x\text{ â¶Ä‰}=\text{ â¶Ä‰}21\text{ â¶Ä‰}−\text{ â¶Ä‰}6x\text{ â¶Ä‰}\\ \\ −\text{ â¶Ä‰}3(−\text{ â¶Ä‰}7\text{ }+\text{ }2x)=\text{ â¶Ä‰â€‰â¶Ä‰}21\text{ â¶Ä‰}−\text{ â¶Ä‰}6x\text{ â¶Ä‰}\end{array}$

Correct Option is A.