Which of the following numbers is irrational?
a. 2/3
b. -√81
c. 5.
d. √2

options C and D

Step-by-step explanation:

An Irrational Number is a real number that cannot be written as a simple fraction.

A . 2/3 is a rational number because it is a fraction

B . - = -9 which could be written as -9/1 , so it is a rational number

C. 5.76262... is irrational because the decimal has no end point

D. is a common example of irrational number , because finding the square root of 2 is also continuous .

Therefore , options C and D are irrational