'Unable' in the Bible

And the Lord was with Judah; and he took the hill-country for his heritage; but he was unable to make the people of the valley go out, for they had war-carriages of iron.

So {the anger of Yahweh was kindled} against Israel, and he gave them into the hand of plunderers; and they plundered them, and he sold them into the hand of their enemies from all sides. They were unable to withstand their enemies any longer.

But if you are unable to tell me, then you shall give me thirty linen wraps and thirty changes of clothes.” And they said to him, “Propound your riddle, that we may hear it.”

So he said to them:Out of the eater came something to eat,and out of the strong came something sweet.After three days, they were unable to explain the riddle.