We divide all the real numbers in two sets, they are rational numbers and irrational numbers. Rational numbers are like - 5/3, 23/40, 125/100 etc. The irrational numbers are like 2.3857…., - 5. 4737…, square root of 3, pi, Euler’s number (e), and any number in decimal representation where the digits are continuing. In other words all integer values, natural numbers, whole numbers, rational numbers, irrational numbers and decimal numbers also called real numbers. The real numbers may be algebraically positive numbers or negative numbers, zero, rational numbers, large number and small numbers, irrational number.
For example 1, 2, 3, 4, 5, 6, square root 5, -23, pi , cube root 10 are all real numbers because they are not imaginary roots. We can indicate all Real numbers by R. Let us see some real numbers symbols, which are used in addition, subtraction, division or multiplication etc. (=) stands for equality, (+) stands for addition, (-) stands for subtraction, stands for less than (<), stands for greater than (>), (×) stands for equal to, (÷) stands for division, square root of 5 is all real numbers. Let us see some examples based on them.
Example 1: - Solve 34 + 12 (43- 39)
Solution: - For this equation, PEMDAS rule will be used
34 + 12 (43 – 39)
= 34 + 12 (4)
= 34 + 48
Example 2: - Solve 2x + 3 > 9 find the value of x.
Solution: - For this inequality, PEMDAS rule will be used
2x + 3 > 9
= 2x > 9 – 3
= 2x > 6
= x > 3