A=0.45 ;Terminating
B=0.26666.....;Non-Terminating
Explanation:
In both the fractions the numerator is less than the denominator thereby indicating that the decimal equivalent is definitely less than one.
Now for A-
We are making the denominator to a multiple of 10.

Now for B-
Using normal long division, divide 4 by 15.
;reminder at each step;calculation of the decimal equivalent
15×2=30;10 ;0.2
15×6=90;10 ;0.26
15×6=90;10 ;0.266
15×6=90;10 ;0.2666
15×6=90;10 ;0.26666
and so on....
Therefore we can see that the reminder is remained constant throughout so there the decimal equivalent is non-terminating.