If 𝑥 + 𝑦 = 5 and 𝑥𝑦 = −3, then 𝑥^{2} + 𝑦^{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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