Difficult to be sure about the first instance; you are passing an Integer object; as you know,
Java is pass-by-value, so the method cannot change the value of the origin of its parameters. It probably unboxes the Integer (7) to an int and increments it to 8; whether it is boxed again I don't know. That might actually be a meaningless question.
You will remember that the ++ operator increases m, but the expression m++ returns the old value, 7. Then when you get to the other m it has the value 8. Remember that Java always works from left to right, and that the postfix operator has a higher precedence than any other arithmetic operator. So you are calculating 7 * 8 (56), not 8 * 7.
In the 2nd example, it is easier to understand.
You pass 7, increment it to 8 and return the old value, again calculating 7 * 8 and getting 56.
The problem is that the expression m++ returns 7 when the value of m is 8.
Remember post-increment expressions return the old value, and pre-increment expressions return the new value.