If the sum of two positive integers is 20 and the difference of their squares is 40, what is the product of the two integers? Answers:
A) 108
B) 99
C) 128
D) 135
E) 143
Let the 2 positive numbers x and y   x+ y = 20 -- 1   x^2 - y^2 = 40   =&gt; (x+y)(x-y)=40 -- 2   Using equation 1 in 2 , we get   =&gt; x-y = 2 -- 3   Solving equation 1 and 3 , we get   x= 11   y= 9   Product = 11*9= 
<gadget id="calculator">11*9</gadget>
<output>99</output>
99   Answer 99
<result>B</result>
If the sum of two positive integers is 20 and the difference of their squares is 40, what is the product of the two integers?