'Able' in the Bible

Now therefore, please make a pledge to my master the king of Assyria, and I will give you two thousand horses, if you are able on your part to set riders on them.

Thus says the king, 'Don't let Hezekiah deceive you; for he will not be able to deliver you.

Therefore evil will come on you; you won't know when it dawns: and mischief will fall on you; you will not be able to put it away: and desolation shall come on you suddenly, which you don't know.

"Stand now with your enchantments, and with the multitude of your sorceries, in which you have labored from your youth; if so be you shall be able to profit, if so be you may prevail.