text: ax + by > cx + dy\nMove the x's to the left side by subtracting cx from each side, and move the y's to the right side by subtracting by from each side\nax - cx > dy - by\nFactor x from the left side and y from the right side\nx(a-c) > y(d-b)\nNow multiply each side by -1 (remember that the inequality sign flips when you multiply each side by a negative number)\nx(a-c)(-1)< y(d-b)(-1)\nDistribute the negative one through each side\nx(-a+c)< y(-d+b)\nNow since x<y, then \n-a+c < -d+b\nNow rearrange the above equation so that it looks like one of your choices.\nAdd a to each side and add d to each side.\nc+d < a+b or \na+b > c+d\nso your answer is choice (3).