Can you find two numbers with a difference of 5 between them?

The difference of their squares must be 45.

?2014-07-20T19:34:09Z

Favorite Answer

Let's assume X is one of the numbers and Y the other.
Then,
X^2 - Y^2 = 45 (i)
X - Y = 5 (ii)
Divide (i) & (ii)
X + Y = 9 (iii)
Add (ii) & (iii)
2X = 14
X = 7
Y = 2

Ahmed2014-07-21T02:28:51Z

X^2 - Y^2 = 45
X - Y = 5
X = 5 + y
(5 + Y)^2 - Y^2 = 45
25 + 10Y + Y^2 - Y^2 = 45
25 + 10Y = 45
10Y = 45 - 25
10Y = 20
Y = 2
remember : X - Y = 5
X - 2 = 5
X = 7
one of the numbers is 2 and the other is 7

?2014-07-21T02:14:45Z

Let n and m be the numbers
n - m = 5
n^2 - m^2 = 45
so (n-m)(n+m) = 45
or 5 (n+m)= 45
or n+m = 9
Therefore we have
n-m = 5
n+m = 9

Adding the two 2n = 14
n = 7
and m =2