We have to verify if 4/5 and 5/6 are eqauivalent to 2/3.
We can verify this dividing the numbers by 2/3, and if we get the value 1, then they are equivalent. If they are equivalent, then the fraction can be reduced up to 2/3, and this division will give us the value 1.
We start with 4/5:
![((4)/(5))/((2)/(3))=(4)/(5)\cdot(3)/(2)=(12)/(10)=(6)/(5)\\eq1](https://img.qammunity.org/2023/formulas/mathematics/college/nf8atjndy6x97xattp93tat68phq59zh4z.png)
4/5 is not a 2/3 ratio.
We continue with 5/6:
![((5)/(6))/((2)/(3))=(5)/(6)\cdot(3)/(2)=(15)/(12)=(5)/(4)\\eq1](https://img.qammunity.org/2023/formulas/mathematics/college/h1mkf2ao06vbxt6wi6bqrrlba34ucztewt.png)
5/6 is not a 2/3 ratio.