91Ó°ÊÓ

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

Constants: - In any expression or equation, the constants are the values that are 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.

The given expression is:

$\left|x−4\right|=10$

Calculation:

Let t be the temperature in Canada at night.

So, the temperature in Canada at night can be $4Â\pm 10$. The base temperature is 4 and it can fluctuate up and down 10.