Chapter 5.5, Problem 12CYU

To determine

Tosolve:The given equation

Answer to Problem 12CYU

  $k<12$

  

Explanation of Solution

Given information:

  $-2\left(k-2\right)>-20$

Concept Used:

When two quantities are not equal, the comparison between them is often presented by certain symbols, this comparison is known as inequality and the symbols used for such comparison are known as inequality symbols.

There are four inequality symbols, $>$ , $<$ , $\ge$ , $\le$ namely “greater than”, “less than”, “greater than or equal to” and “less than or equal to” respectively.

On a number line, integers are placed at an interval of one and value if integers increases as we move left to right on the number line.

Calculation:

  $\begin{array}{l}-2\left(k-2\right)>-20\\ \Rightarrow -2k+4>-20\mathrm{...}\left(\text{Distributive property}\right)\\ \Rightarrow -2k+4-4>-20-4\mathrm{...}\left(\text{subtraction property of inequality}\right)\\ \Rightarrow -2k>-24\\ \Rightarrow \frac{-2k}{-2}<\frac{-24}{-2}\mathrm{...}\left(\text{division by negative number reverses inequality}\right)\\ \Rightarrow k<12\end{array}$

Graph:

In the inequality $k<12$ we can say $k$ in smaller than 12 and can plot the same on number line-

We will make an open dot on 12 as it is not included in the inequality and then move towards left as $k$ in smaller than 12.