Where would point B’ be?

When finding a point in the graph, you always look at the x-axis first and then the y. You would write it the same way too. The x-axis is horizontal whereas the y is vertical. Take a look at point B and trace it up to the x line. It lines up with -2. Do the same for the y and you'll see it lines up with -2. Then answer would be (-2, -2). X always goes first within the parenthesis, then the y.