If π₯ + π¦ = 5 and π₯π¦ = β3, then π₯2 + π¦2 is equal to
We have \((x+y)^2=x^2+y^2+2xy\)
So \(x^2+y^2=(x+y)^2-2xy\)
Here: \(x^2+y^2=5^2-2(-3)\text{ ... or ... }x^2+y^2=25+6\rightarrow31\)
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