X and Y are equal to the expected value of-- I'll switch back to my colors just because this is the final result-- the expected value of X times the expected value of the product of XY minus-- what is this?

X 和 Y 等于预期值——我将切换回我的颜色只是因为这是最终结果——X 的预期值乘以 XY 乘积的预期值减去——这是什么？