Question 945647
How would I multiply this problem (10-√5)(10+√5)? This is what I have (10)(10)+10√5+10√5-√5√5
100-√25
100-5=95 
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That's correct.
You show 10sqrt(5) + 10sqrt(5) ...  one of them is negative.  You did subtract it, tho, and got the right answer.