Here is an example of them both being used:
Although the baby was able to stand while holding on to something, he was still unable to walk.
I am able to go to the mall this weekend, are you?
Completely devoid of fuel, she collapsed in a shivering heap and was unable to mine any more diamonds.
She was able to transcend her own suffering to help others.
The able sailor rove the line quickly through the block.
how to use inexplicable in three sentence's
I was unable to go to the carnival because I had loads of homework.
It's so frustrating that I can't fix it myself, but I am unable to lift it.
"we were unable to get expiation from the local store"
She was unable to go swimming because she was menstruating.
I am unable to describe the cumulonimbus clouds effectively.
We were unable to avoid drifting into the shoal.
It is not acceptable to be unable to use acceptable in a sentence.
I was unable to use the computer for a while, as it was busy updating the system.
He was injured and therefore unable to play in the final round.
The cart was unable to bear the heavy load.
'The beneficiary is unable to speak due to her disabilities' is correct.
The climber was unable to scale the precipitous cliff side.