Answer: apx^2-bpxy+aqxy-bqy^2
Step-by-step explanation: (px+qy)x(ax-by) Multiply each term in the first parenthesis by each term in the second parenthesis (FOIL). That would give you pxax-bpxy+aqxy-qyby. Then calculate the product pxax which would give you apx^2-bpxy+aqxy-qyby. Calculate the other product qyby which would give you apx^2-bpxy+aqxy-bqy^2.