Answer:
To get the value of 31, the expression should be evaluated as follows:
4 + 9 × 5 - 2 = 4 + 45 - 2 = 47
So, we need to insert parentheses to change the order of operations. To get a value of 31, we can add parentheses around 9 × 5, like this:
4 + (9 × 5) - 2 = 4 + 45 - 2 = 47
Since the parentheses force the multiplication to be done before the addition and subtraction, the value of the expression is not changed. Therefore, there is no way to place parentheses in the expression to make its value 31.