The coordinates of the vertices of quadrilateral RSTU are R(−4, 1), S(4, −1), T(3, −6), and U(−5, −4). Which statement correctly describes whether quadrilateral RSTU is a rectangle?

Look, when you want to do something like put it like x^2. x2 could mean x² or x₂. so to clear confusion, know the notation. to find the product multiply the x's and you get -8x and the y's and you get 6y. since it's all being multiplied it is just -8x6y, or answer a. although the better answer is -48xy(combining -8 and 6) because you should multiply constants whenever you can.