Question

12. Which number is an irrational number?
a) square root 2
b) - 4/3
c) 1.8 (there is a line above 8)
d) - square root 8

Answer- D
Am I correct ?

Answer 1

same answer as the last one. Look up definition of rational number please. If you can write it as a ratio of whole numbers it is rational. That applies to all but a) and d)
for example a is sqrt 2 and d is -2sqrt 2
(are you sure d is not the cube root of 8 ?)

Answer 2

I know what's a rational number just that my teacher and i are having trouble in this problem

it's the square root of 8 but it's negative

i most likey think the answer is d thought