



 
Hi Sarah, Look at the difference of squares expression
The two numbers on the right hand side are (x  y) and (x + y) and their difference is
There are two facts to notice here, one is that the difference is even and the second is that the two numbers on the right of the difference of squares expression are x minus half this difference and x plus half this difference. Here is an example
I am looking to see if this can be the right hand side of a difference of squares expression.
Hence 48 = 40 + 8 and 32 = 40  8 and I have
This difference of squares technique worked because 48  32 is even and 40 and 8 are numbers I can easily square. Here is another example
17  13 = 4 so y = 2 and thus
easy if you know that 15^{2} = 225. Now try your problem,  


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