SOLUTION: solve the system algebraically: x^2+y^2=20 please help me thanks a lot

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Question 48473: solve the system algebraically: x^2+y^2=20
please help me
thanks a lot
Answer by longjonsilver(2297) About Me  (Show Source):
You can put this solution on YOUR website!
ok, solve means "where does the curve cross the x-axis?" ie this is where y=0.

So +x%5E2%2By%5E2=20+ becomes
+x%5E2%2B%280%29%5E2=20+
+x%5E2=20+
+x=sqrt%2820%29+ or +x=-sqrt%2820%29+

which are the 2 answers. However, we usually try to simplify a square root if possible. Here we can:
+x=sqrt%2820%29+ or +x=-sqrt%2820%29+
+x=sqrt%284%2A5%29+ or +x=-sqrt%284%2A5%29+
+x=sqrt%284%29sqrt%285%29+ or +x=-sqrt%284%29sqrt%285%29+
+x=2sqrt%285%29+ or +x=-2sqrt%285%29+

jon