Help me im so confused

James adds two numbers a + b. sally adds the same two numbers but reverse the order b + a what property of addition assures us that james and sally will get the same sum

What is the radical expression that is equivalent to the expression 27 1 over 5?

Consider the sequence below. 3 , 1 , 1/3 , 1/9 , select the explicit function which defines the sequence.