The sum of the squares of two numbers is 225 and the square oftheir sum is 441. What is the reciprocal of their product?
+230 Lets first denote x and y as the 2 numbers, so this means:
1.x^2+y^2+225
2.(x+y)^2=441
Expanding the second equation we get that x^2+2xy+y^2+441
Subtracting the 2 equation from the 1st one we get 2xy=441-225 2xy=216 and xy=108
The problem asks for the reciprocal of thier product so 1/xy=1/108
And thus 1/108 is our final answer
