Um, If the bat is $1 more than the ball, the ball cannot be 10¢ because that would make the bat cost $1.10 and the ball would still cost $0.10, thus the total price would be $1.20.
They made the mistake of adding the difference between the bat and the ball to the ball to get the total, not the total of the bat, being a dollar more than the ball plus the cost of the ball.
The bat would have to be $1.05 and the ball would be $0.05, which together then equal $1.10.
I guess AI is only as intelligent as those who program it, which does not impress me in the given example.
x + y = 1.10
x - y = 1.00
2x + (y-y) = 2.10
2x = 2.10
x = 1.05
y = 0.05