91影视

Variables: - In any expression or equation, the variable is an unknown quantity. It may be any alphabet or any special symbol.

In $\left|b+4\right|=2$, b is a variable.

Constants: - In any expression or equation constant are the values which is fixed.

While performing addition in an equation, the same kind of elements or like terms are added together.

Absolute value: - Absolute value of any quantity simply means a positive value of that quantity.

Example: -

Consider a variable x. Here, x can be both positive or negative but $\left|x\right|$will always be positive and hence the absolute value.

Given $\left|b+4\right|=2$.

Case 1: -$b+4=2$

Add $鈭�4$to both sides of the equation.

$\begin{array}{l}b+4鈭�4=2鈭�4\\ b+0=鈭�2\\ b=鈭�2\end{array}$

Case 2: - $b+4=鈭�2$

Add $鈭�4$to both sides of the equation.

$\begin{array}{l}b+4鈭�4=鈭�2鈭�4\\ b+0=鈭�6\\ b=鈭�6\end{array}$

Hence, the values of b are $b=鈭�2$and $b=鈭�6$.

Consider a number line as b. Mark the points $b=鈭�2$and $b=鈭�6$on that number line as shown below.