The difference between the squares of two numbers is 15. Three times the square of the first number increased by the square of the second number is 49. Find the numbers. Solution Let the numbers be x and y Therefore x^2 - y^2=15 3x^2+y^2=49 Solving them we get= 4x^2=64 x^2=16 that gives x=+-4 and when x, we get y= +-1 and when x=-4, we get y= +-1.