The sum of two numbers is 20 and the sum of their squares is 140.
The sum of two numbers is 20 and the sum of their squares is 140. Find the product of the two numbers.
Answer/Solution
130
Steps/Work
Let a and b be the two numbers
(a+b)^2=a^2+2ab+b^2
Given (a+b)=20 a^2+b^2=140
So, 20^2=140+2ab
2ab=400-140
2ab=260
ab=130
Ans A
(a+b)^2=a^2+2ab+b^2
Given (a+b)=20 a^2+b^2=140
So, 20^2=140+2ab
2ab=400-140
2ab=260
ab=130
Ans A